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through Real-Time Traffic Information Systems Are Expanding but Face 
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Report to Congressional Requesters: 

United States Government Accountability Office: 
GAO: 

November 2009: 

Surface Transportation: 

Efforts to Address Highway Congestion through Real-Time Traffic 
Information Systems Are Expanding but Face Implementation Challenges: 

GAO-10-121R: 

GAO Highlights: 

Highlights of GAO-10-121R, a report to congressional requesters. 

Why GAO Did This Study: 

Growing congestion on our nation’s roads results in wasted time and 
fuel, which adversely affects the economy and the environment. State 
and local government agencies and private companies disseminate real-
time traffic information to help travelers decide whether to use 
alternative, less congested routes. Legislation enacted in 2005 
required the U.S. Department of Transportation (DOT) to establish the 
Real-Time System Management Information Program, in order to provide 
states the capability to monitor traffic and travel conditions on major 
highways and share that information. As requested, this GAO report 
addresses, among other things, (1) how the public and private sectors 
disseminate real-time traffic information to the public, (2) actions 
DOT has taken to establish the Real-Time System Management Information 
Program, and (3) experts’ views on the need for a nationwide real-time 
traffic information system and its potential characteristics. 

To conduct this study, GAO visited sites in California and Florida, 
which have well-developed traffic information systems; reviewed and 
analyzed DOT reports and data; and interviewed transportation 
officials, experts, and other stakeholders. GAO is not making any 
recommendations at this time because DOT has not finalized the proposed 
rule it issued in January 2009, and there was no consensus from the 
experts GAO interviewed as to whether an increased federal role in this 
area is appropriate or what this role might be. 

What GAO Found: 

States and local agencies and the private sector use a variety of 
services and technologies to disseminate real-time traffic information 
to the public. For example, state and local agencies deploy electronic 
traffic signs and services that provide information via a nationwide 
511 phone number, and private companies operate Web sites that provide 
information for cities across the country. The coverage provided by 
these services and technologies is expanding, but there are gaps in 
coverage and variations in aspects of real-time traffic information, 
such as the quality of the data collected and the extent to which state 
and local agencies share their data. The private sector is expanding 
coverage, in part by using newer technologies to increase the 
collection of traffic data. Like the public sector, the private sector 
faces limitations to its coverage and data quality. 

To establish the Real-Time System Management Information Program, DOT’s 
Federal Highway Administration (FHWA) issued a proposed rule in January 
2009 that, when finalized, could improve the coverage, quality, and 
sharing of traffic information. The rule proposes requirements for 
states to make available certain traffic information, such as travel 
time, on major highways and to meet data quality standards, including 
standards for timeliness. State and local government officials GAO 
interviewed said that these improvements would allow the public to 
better select the most efficient route to reach their final 
destination, which could reduce congestion and yield other benefits. 
Yet state and local officials also told GAO that the proposed rule’s 
time frames to develop the program are too short and would be difficult 
to implement without additional funds. DOT expects to issue the final 
rule in February 2010 and is currently considering options to address 
such concerns. According to FHWA, its division offices will monitor 
states’ compliance with the final rule. 

Experts GAO interviewed generally agreed that a nationwide real-time 
traffic information system is needed to help address current gaps in 
information coverage and inconsistencies in data quality. Many of these 
experts noted that reported mobility and environmental benefits, such 
as travel time savings and reduced emissions, could be increased under 
a nationwide system. However, experts held varying views on the 
potential characteristics of such a system. Some said that the 
anticipated results of current efforts related to real-time traffic 
information by DOT, states, and the private sector would lead to the 
development of a nationwide real-time traffic information system and 
considered these efforts sufficient. Others envisioned a nationwide 
system that would go beyond current efforts. For example, in their 
visions, DOT would take a strong leadership role or partner more with 
the private sector to disseminate information. However, experts cited 
potential challenges in designing and implementing a nationwide system, 
including reaching consensus on the form of the nationwide system and 
funding constraints. 

DOT reviewed a draft of this report and provided a technical comment 
that GAO incorporated. 

View [hyperlink, http://www.gao.gov/products/GAO-10-121R] or key 
components. For more information, contact David J. Wise at (202) 512-
2834 or wised@gao.gov. 

[End of section] 

November 30, 2009: 

Congressional Requesters: 

Growing congestion on our nation's roads is a challenge for many 
metropolitan and nonmetropolitan areas. Traffic congestion results in 
wasted time and fuel for travelers and commercial truckers, thereby 
adversely affecting the economy and the environment. According to 
transportation researchers, in 2007, congestion in urban areas resulted 
in 4.2 billion hours of time spent waiting in traffic and 2.8 billion 
gallons of extra fuel used, at a total cost of $87.2 billion.[Footnote 
1] Among the tools that the U.S. Department of Transportation (DOT) has 
identified to help reduce congestion are real-time traffic information 
systems and technologies,[Footnote 2] which can be used to disseminate 
traffic information to the public to help travelers--including 
commuters and long-distance travelers--decide whether to use 
alternative, less congested routes. 

Agencies in state governments and metropolitan areas, as well as 
private companies, deploy and operate real-time traffic information 
systems and technologies to provide traffic and travel information to 
the public. Recognizing the potential for real-time traffic information 
to decrease congestion, Congress incorporated requirements related to 
real-time traffic information into the 2005 authorization of federal 
surface transportation programs. Specifically, the Safe, Accountable, 
Flexible, Efficient Transportation Equity Act: A Legacy for Users 
(SAFETEA-LU) made DOT responsible for establishing a program--called 
the Real-Time System Management Information Program--that would provide 
all states the capability to monitor real-time traffic and travel 
conditions on major highways and enable them to share that information 
with state and local governments and the traveling public.[Footnote 3] 
Furthermore, DOT has identified real-time traffic information 
initiatives as high-priority efforts to address congestion. 

Given the potential benefits of real-time traffic information to the 
nation, the House Committee on Transportation and Infrastructure asked 
us to provide information on existing real-time traffic information 
systems, current and potential future efforts to improve such systems 
and create a nationwide system, as well as the impacts and costs of 
existing systems. Our objectives for this review were to determine (1) 
how state and local agencies and the private sector disseminate real- 
time traffic information to the public, and the completeness of current 
coverage; (2) what actions DOT has taken to establish the Real-Time 
System Management Information Program required by SAFETEA-LU, and 
stakeholders' views on these actions; and (3) how selected experts view 
the need for and benefits of a nationwide real-time traffic information 
system, how they envision such a system, and what the related 
challenges may be. The results of our work are contained in enclosure 
I. To address the committee's interest in the impacts and costs of 
existing systems, we examined what studies have found about the 
impacts--particularly on mobility, the environment, and the economy-- 
and the costs of these systems. These issues are discussed in enclosure 
II. This report focuses on real-time traffic information that is 
disseminated to the public.[Footnote 4] 

To address the first objective, we interviewed--and reviewed relevant 
reports and studies obtained from--DOT officials; representatives of 
national organizations involved in real-time traffic information 
initiatives, such as the Intelligent Transportation Society of America; 
state and local transportation officials; and private companies 
involved in real-time traffic information initiatives.[Footnote 5] We 
also conducted site visits in California and Florida[Footnote 6] and 
analyzed 2007 data from DOT surveys on the deployment of Intelligent 
Transportation System (ITS) technologies, including real-time traffic 
information technologies, to determine the types of real-time traffic 
information technologies used in metropolitan areas and the coverage 
provided by these technologies.[Footnote 7] To address the second 
objective, we reviewed relevant sections of SAFETEA-LU, interviewed DOT 
officials on actions the department has taken to address SAFETEA-LU's 
requirement that DOT establish the Real-Time System Management 
Information Program, and reviewed DOT's proposed rule and guidance 
related to this program. To determine stakeholders' views on DOT's 
proposed program, we interviewed selected state and local officials and 
two private companies that provide real-time traffic data, and also 
analyzed comments that stakeholders submitted to DOT on the proposed 
program.[Footnote 8] To address the third objective, we interviewed 19 
experts from DOT, state and local transportation agencies, academia, 
and the private sector. (See enclosure III, table 6.) We identified 
these experts with assistance from the National Academy of Sciences, 
seeking geographic diversity and expert knowledge of various aspects of 
real-time traffic information systems and technologies. Finally, to 
obtain information on the impacts and costs of real-time traffic 
information systems, we identified and reviewed relevant studies from 
selected literature databases. The studies we reviewed quantified the 
impacts of real-time traffic information technologies and systems, 
discussed the costs, or reported the results of benefit-cost analyses. 
We reviewed the methodologies of these studies to ensure that they were 
sound and determined that they were sufficiently reliable for our 
purposes. 

We conducted this performance audit from January 2009 to November 2009, 
in accordance with generally accepted government auditing standards. 
Those standards require that we plan and perform the audit to obtain 
sufficient, appropriate evidence to provide a reasonable basis for our 
findings and conclusions based on our audit objectives. We believe that 
the evidence obtained provides a reasonable basis for our findings and 
conclusions based on our audit objectives. Additional information about 
our scope and methodology is provided in enclosure III. 

Background: 

Real-time traffic information systems, along with other types of ITS, 
can be used to improve traffic flow and reduce congestion.[Footnote 9] 
Traffic congestion results from many sources, such as recurring high 
levels of daily traffic, as well as nonrecurring events like traffic 
incidents, special events, and bad weather that can limit the usable 
physical capacity of existing roadways. Existing research has shown 
that real-time traffic information systems can alleviate traffic 
congestion by providing travelers with information on traffic and other 
travel conditions, as well as on alternative routes. See enclosure II 
for information regarding this research. Real-time traffic information 
is one type of traveler information disseminated to the public. Other 
types of traveler information include transit, weather, and parking 
information. 

State and local agencies, as well as private companies, deploy real- 
time traffic information systems that collect real-time traffic data 
using various technologies, aggregate and translate these data into 
useful information, and disseminate that information to the public 
using various technologies (see fig. 1).[Footnote 10],[Footnote 11] The 
technologies that support real-time traffic information collection and 
dissemination are rapidly evolving. Travelers, for example, are 
increasingly using newer technologies--such as cell phones that can 
access Web sites and receive text messages and in-vehicle navigation 
devices--to obtain traffic information during travel.[Footnote 12] 

Figure 1: Examples of Technologies Associated with Real-Time Traffic 
Information Systems: 

[Refer to PDF for image: illustration] 

Data collection: 
Real-time traffic data are collected using various technologies: 
* Aerial surveillance helicopters; 
* Video surveillance cameras; 
* Fixed sensors[A]; 
* Vehicle probes[B]. 

Data aggregation and translation: 
Private and public entities aggregate and translate these data into 
information. 

Information dissemination: 
Information is disseminated to the public through various technologies: 
* Telephone; 
* Television; 
* Internet; 
* Radio/highway advisory radio[C]; 
* Dynamic message signs[D]; 
* Devices used in vehicles (e.g., cell phones, navigation devices). 

Source: GAO. 

[A] A fixed sensor is a technology that is stationary at the roadside 
or embedded in the road to monitor traffic flow. 

[B] Vehicle probes use roaming vehicles and portable devices to collect 
data on travel times. Vehicle probes include cell phones and Global 
Positioning System (GPS) devices. 

[C] Highway advisory radio uses radio stations to broadcast traffic-and 
travel-related information to travelers using AM radio. 

[D] Dynamic message signs are permanent or portable electronic traffic 
signs that give travelers information on traffic conditions and travel 
times, among other things. 

[End of figure] 

Real-time traffic information systems disseminate various types of 
information to the public such as: 

* road closure information, including road or lane closures that result 
from construction, maintenance, special events (such as parades), 
crashes or other incidents; 

* weather conditions affecting roadways and road conditions; and: 

* traffic flow information, such as travel times, travel delays, or 
vehicle speeds. 

Travelers can use real-time traffic information to help make decisions 
before they travel (pre-trip) and during travel (en route). The need 
for various types of information depends on the traveler. For example, 
to reach their destination as efficiently as possible, some commuters 
may need pre-trip information, such as travel delays or times, so that 
they can adjust their route or time of departure. Commercial drivers 
may be more concerned with obtaining en route information, such as 
construction or roadway conditions, since their long itinerary does not 
allow them to observe real-time traffic conditions for their entire 
trip prior to their departure. Interregional travelers may need traffic 
information for both their origin and destination, sometimes requiring 
them to retrieve information from several real-time traffic information 
systems operated by various agencies. 

DOT promotes the deployment of real-time traffic information 
technologies. For example, DOT's ITS Joint Program Office and the 
Federal Highway Administration (FHWA) promote the deployment of these 
technologies through activities such as conducting research, providing 
technical assistance to state and local agencies, and acting as a 
clearinghouse for guidance, best practices, and lessons learned. In 
addition, DOT's Research and Innovative Technology Administration 
(RITA) ITS Web site includes both deployment statistics and databases 
on the benefits and costs of various ITS technologies, including real- 
time traffic technologies. Furthermore, DOT, through cooperative 
agreements with standards development organizations such as the 
Institute of Transportation Engineers, helps to develop ITS standards 
that define, among other things, how ITS systems (including real-time 
traffic information systems), products, and components can exchange 
information. In 2005, SAFETEA-LU gave DOT the responsibility of 
establishing the Real-Time System Management Information Program. 
SAFETEA-LU also required DOT to establish data exchange formats to 
facilitate the sharing of traffic data across jurisdictional boundaries 
and the availability of traffic information nationwide. DOT is 
currently developing an ITS strategic plan that will identify the 
direction, goals, and objectives for the department's ITS program over 
the next 5 years. In developing this strategic plan, DOT is working to 
further define its role in promoting real-time traffic information 
systems. 

Agency Comments: 

We provided a draft of this report to DOT for its review and comment. 
DOT officials provided a technical comment on our report, which we 
incorporated. 

We are sending copies of this report to interested congressional 
committees and the Secretary of Transportation. The report also is 
available at no charge on the GAO Web site at [hyperlink, 
http://www.gao.gov]. 

If you or your staff have any questions on this report, please contact 
me at (202) 512-2834 or wised@gao.gov. Contact points for our Offices 
of Congressional Relations and Public Affairs may be found on the last 
page of this report. GAO staff who made contributions to this report 
are listed in enclosure IV. 

Signed by: 

David J. Wise:
Director, Physical Infrastructure Issues: 

Enclosures: 

List of Requesters: 

The Honorable James L. Oberstar:
Chairman:
The Honorable John L. Mica:
Ranking Member:
Committee on Transportation and Infrastructure:
House of Representatives: 

The Honorable Peter A. DeFazio:
Chairman:
The Honorable John J. Duncan, Jr.
Ranking Member:
Subcommittee on Highways and Transit:
Committee on Transportation and Infrastructure:
House of Representatives: 

The Honorable Mike Rogers:
House of Representatives: 

The Honorable Russ Carnahan:
House of Representatives: 

[End of section] 

Enclosure I: 

Public and Private Sectors Use a Variety of Dissemination Technologies 
but Gaps in Coverage Exist: 

Dissemination and Coverage: 

Federal Role: 

* The Department of Transportation (DOT) initiated the development of 
511 Traveler Information Services by asking the Federal Communications 
Commission (FCC) to set aside a three-digit telephone number nationwide 
for traveler information services. FCC granted this request in July 
2000 and issued a rule on 511 stating that DOT’s role was to 
“facilitate ubiquitous deployment” of these services. The rule went 
into effect in February 2001. 

* In response, DOT helped form the 511 Deployment Coalition—a coalition 
of public agencies, industry groups and associations, and private 
companies—to encourage the growth of 511 services. 

* DOT provided technical expertise and limited start-up funds. DOT 
offered money to all states, up to $100,000, for planning the 
implementation of 511 services. 

* DOT’s current role is to 

- provide “targeted assistance” with the goal of having 511 deployed 
nationwide, and 

- create awareness of the 511 system. 

DOT has carried out various activities to promote the deployment of 
real-time traffic information technologies by state and local 
governments, in addition to its efforts to promote 511 services. For 
example, 

* DOT distributes information on best practices, Intelligent 
Transportation Systems (ITS) standards, and lessons learned related to 
the deployment of these and other ITS technologies. DOT also provides 
some technical assistance on ITS. 

Funding Sources: 

DOT does not provide funding to state and local governments 
specifically for the deployment of real-time traffic information 
technologies and systems. 

* The Safe, Accountable, Flexible, Efficient Transportation Equity Act: 
A Legacy for Users (SAFETEA-LU) authorizes states to use their annual 
federal-aid highway funding for developing and implementing these 
technologies and systems. (These funds are derived from the Highway 
Trust Fund and are provided to the states mostly through formula grant 
programs.) 

* States generally finance real-time traffic information systems and 
technologies using a combination of federal and state funds. However, 
the proportions vary. For example, California officials told us that 
they have mainly used state funds while Florida officials told us that 
they have mainly used federal funds. 

State and Local Agencies Disseminate Traffic Information through 511 
Traveler Information Services: 

* Most states and some local agencies disseminate traffic information, 
as well as other types of traveler information, through 511 Traveler 
Information Services (see figure 2). 

- These services provide information via the telephone (using an 
interactive voice response automated system) and the Internet. By 
dialing the three-digit number or accessing the state or local 511 Web 
site, travelers can obtain various types of traveler information, 
including information on traffic and road conditions as well as 
construction- and weather-related traffic problems. 

- The types of information provided by these services vary. For 
example, some services provide information on travel times and roadway 
weather conditions, while others do not. In addition, the way that 
information is presented on 511 Web sites varies. 

* According to the 511 Deployment Coalition, as of September 2009, 39 
services were operating in 36 states. In addition, 511 services were 
available to over 181 million Americans (60 percent of the population), 
according to DOT. 

- Thirty-two were statewide services. 

- Seven were metropolitan or regional services. California has four 511 
services operating within its borders. 

- Some metropolitan or regional 511 services, such as those in 
California, are operated by local agencies; while others, such as those 
in Missouri and Massachusetts, are operated by the respective state 
department of transportation. 

* While the volume of calls received by 511 services varies 
significantly, overall, these services have received a large number of 
calls. According to the 511 Deployment Coalition, as of July 2009, 
these services have received over 151 million calls nationwide since 
their inception in 2001.[Footnote 13] 

* 511 services are expanding. For example, Pennsylvania launched its 
service in September 2009, and a five-county system in Southern 
California is expecting to launch its service by the end of 2009. Four 
additional states—Delaware, Maryland, Mississippi, and South Carolina—
are planning to have operational 511 services in 2010. 

* Although 511 services are expanding, some states, such as Texas and 
Michigan do not plan to implement such services. States without 511 
services may choose not to establish them because they lack adequate 
traffic data and funding. Furthermore, rather than using 511 services, 
some states may disseminate traffic information using other methods, 
such as the Internet and dynamic message signs. 

Figure: 511 roadside signs, like the one shown above, are used to 
promote awareness of the 511 travel service: 

[Refer to PDF for image: photograph] 

Source: San Francisco Bay Area’s Metropolitan Transportation
Commission. 

[End of figure] 

Figure 2: Status of 511 Traveler Information Services, as of September 
2009: 

[Refer to PDF for image: U.S. map and associated data] 

511 is operational: 
Alaska: 
Arizona: 
Colorado: 
Florida: 
Georgia: 
Idaho: 
Iowa: 
Kansas: 
Kentucky: 
Louisiana: 
Maine: 
Minnesota: 
Montana: 
Nebraska: 
Nevada: 
New Hampshire: 
New Jersey: 
New Mexico: 
New York: 
North Carolina: 
North Dakota: 
Oregon: 
Pennsylvania: 
Rhode Island: 
South Dakota: 
Tennessee: 
Utah: 
Vermont: 
Virginia: 
Washington: 
Wisconsin: 
Wyoming: 

511 expected to be operational by 2010: 
California: 
Delaware: 
Maryland: 
Mississippi: 
South Carolina: 

511 not expected to be operational by 2010: 
Alabama: 
Arkansas: 
Connecticut: 
District of Columbia: 
Hawaii: 
Illinois: 
Indiana: 
Massachusetts: 
Michigan: 
Missouri: 
Ohio: 
Oklahoma: 
Texas: 
West Virginia: 

Metropolitan or regional area with 511 service: 
Sacramento/Northern California regional area: 
San Francisco Bay metropolitan area: 
Eastern Sierra regional area: 
San Diego regional area: 
St. Louis metropolitan area: 
Cincinnati/Northern Kentucky regional area: 
Eastern Massachusetts regional area: 

Sources: 511 Deployment Coalition (data); MapArt (base map). 

[End of figure] 

State and Local Agencies Use Other Methods for Disseminating Real-time 
Traffic Information: 

* Based on DOT’s most recent surveys of ITS deployment in large 
metropolitan areas (conducted in 2007), state and local agencies in 
these areas disseminated real-time traffic information to the public 
primarily through the Internet, e-mail, television and radio, dynamic 
message signs, and Highway Advisory Radio.[Footnote 14] 

* These technologies provided information on traffic incidents, travel 
time, and travel speeds on roads in these metropolitan areas.[Footnote 
15] 

- Most metropolitan areas disseminated information on traffic 
incidents, and significantly fewer disseminated information on travel 
times and travel speeds. (See table 1.) 

- State and local agencies disseminated information on freeways more 
frequently than on arterial roads.[Footnote 16] (See table 1.) 

Table 1: Percentage of Metropolitan Areas in Which Incident, Travel 
Time, and Travel Speed Information Was Disseminated to the Public in 
2007: 

Type of information: Incident; 
Percentage of metropolitan areas: Freeways: 87%; 
Percentage of metropolitan areas: Arterial roads: 68%. 

Type of information: Travel time; 
Percentage of metropolitan areas: Freeways: 36%; 
Percentage of metropolitan areas: Arterial roads: 19%. 

Type of information: Travel speed; 
Percentage of metropolitan areas: Freeways: 32%; 
Percentage of metropolitan areas: Arterial roads: 16%. 

Source: GAO analysis of DOT data. 

Note: These percentages are based on responses from state and local 
agencies in large metropolitan areas to DOT surveys on freeway 
management and arterial management. Ninety-four metropolitan areas 
responded to the freeway management survey in 2007 (about an 89 percent 
response rate), and 102 metropolitan areas responded to the arterial 
management survey in 2007 (about a 95 percent response rate). See 
enclosure III for more information on the surveys. 

[End of table] 

* Some states are collaborating to disseminate traffic information 
across states or across multiple agencies within a jurisdiction. For 
example: 

- Northwest Passage Corridor Coalition: Wisconsin, Minnesota, North 
Dakota, South Dakota, Montana, Wyoming, Idaho, and Washington 
coordinate the information they disseminate to the public, particularly 
on interstates that cross multiple states. 

- Transportation Operations Coordinating Committee (TRANSCOM): State 
and local agencies in New York, New Jersey, and Connecticut formed this 
coalition, which collects and disseminates real-time incident and 
construction information to over 100 member agencies and the public in 
the New York metropolitan area. 

- I-95 Corridor Coalition: States along the I-95 Corridor, from Maine 
to Florida, formed this coalition, which provides information via a Web 
site on traffic conditions and travel time. 

Dynamic message signs, like the one shown above, are electronic 
roadside signs displaying traveler information that can be updated in 
real time. These signs can provide travelers with en route information 
on incident and closures, travel times, and traffic and weather 
conditions. Source: DOT. [See PDF for image: photograph] 

The images shown at this traffic management center, located in Orlando, 
Florida, were taken from traffic cameras. The traffic cameras collect 
real-time traffic data, and the center aggregates the data from the 
cameras and from other technologies and then disseminates relevant 
traffic information to the public. Source: Florida Department of 
Transportation. [See PDF for image: photograph] 

Geographic Coverage Provided by State and Local Data Collection 
Technologies Is Limited: 

* Although state and local agencies disseminate traffic information 
through various methods, the information available for dissemination to 
the public is limited because the geographic coverage of the 
technologies the agencies deploy within their areas of operations to 
collect traffic data, such as fixed sensors and cameras, is limited. 

* Based on DOT’s 2007 surveys, technologies used by state and local 
agencies for collecting real-time traffic data covered about 39 percent 
of the combined freeway miles in the 64 large metropolitan areas that 
provided this information.[Footnote 17] While the percentage is up from 
33 percent reported for 2004, it reveals a significant gap, given that 
freeways account for the majority of the nation’s traffic, congestion, 
and travel time variability. 

- The cost of deploying and maintaining technologies that collect 
traffic data, such as fixed sensors, is a major factor limiting the 
roadway mileage public agencies can cover. 

* Although DOT does not have comparable information on the collection 
of traffic data for arterial and rural roads, DOT and state officials 
told us that coverage is significantly lower for these roads than for 
freeways. 

- The main factor limiting the collection of accurate data on arterial 
roads is cost because more data collection technologies are needed to 
capture traffic data between the many entrances and exits on arterial 
roads (e.g., for gas stations, shopping centers, and buildings). Also, 
arterial traffic is a greater challenge to measure because signalized 
intersections often interrupt traffic flow and make it harder to 
predict. 

- The coverage in rural areas is lower mainly because the delivery of 
power and communications to real-time traffic detection technologies in 
isolated areas can be cost prohibitive unless there is a specific 
safety demand—such as a high crash rate. Additionally, congestion in 
rural areas is much lower than in metropolitan areas, lessening the 
need for real-time traffic information. 

Measures of Data Quality: 

Good data quality is needed to provide useful information to travelers 
so that they can make the most efficient travel decisions. The quality 
of traffic data is determined by the data’s timeliness, accuracy, and 
availability. 

* Timeliness—the time from when an event or condition occurs to when it 
is reported by real-time information dissemination technology. 

* Accuracy—how close the reported data are to “ground truth,” or actual 
conditions. 

* Availability—how much of the data designed to be collected by the 
real-time information collection technology is actually made available. 

State and Local Agencies Vary in the Quality of the Traffic Data They 
Collect and the Extent to Which They Share Traffic Information: 

* The quality of real-time traffic data collected, including the data’s 
timeliness, accuracy, and availability, varies by state and local 
government. 

- The timeliness of dissemination to the public depends on the type of 
information disseminated (i.e., incident information, travel time) or 
geographic location (i.e., metropolitan or nonmetropolitan area). For 
example, it may take longer to disseminate information in rural areas 
compared with urban areas because state DOTs may not have the available 
resources or infrastructure to collect and report information quickly 
in rural areas. 

- Although a key data collection technology used by public agencies—
fixed sensors embedded in the roadway—is generally accurate, there is 
variation in how reliably these sensors function. In cases where 
sensors do not function, traffic data are not available from them. In 
California, for example, some districts have sensors that function 50 
percent of the time, while other districts’ sensors function 90 percent 
of the time. The poor reliability of the sensors in some districts is 
generally due to hardware failure, such as broken wiring and missing 
parts. 

* The extent to which states and local agencies share or exchange data 
and information varies. 

- According to the 511 Deployment Coalition, there are three basic ways 
to transfer and share data or information from 511 systems: calls, data 
transfer, and application or database sharing—23 services currently 
transfer calls, 0 transfer data, and 9 share applications or databases. 
(See table 2.) 

- Some states, such as Alaska, Louisiana, Massachusetts, and Missouri, 
do not transfer calls, transfer data, or share databases or 
applications. The main reason these states do not share data, 
particularly through data transfer or database sharing, is that they do 
not want to incur the cost of matching data or developing a matching 
database for two or more systems. 

Table 2: Extent to Which 511 Services Share or Exchange Data and 
Information: 

How information and data are shared: Call transfer: One 511 system 
transfers calls to another 511 system.
Number of states and metropolitan/regional areas: 23; 
States and metropolitan/regional areas: Sacramento, Cincinnati/Northern 
Kentucky, Colorado, Florida, Georgia, Idaho, Iowa, Kansas, Maine, 
Montana, New Jersey, North Dakota, New Hampshire, New Mexico, New York, 
North Carolina, South Dakota, Tennessee, Utah, Vermont, Virginia, 
Washington, Wisconsin. 

How information and data are shared: Data transfer: The underlying data 
systems are accessible to other 511 systems, enabling those systems to 
exchange information with neighboring jurisdictions without 
transferring calls.
Number of states and metropolitan/regional areas: 0; 
States and metropolitan/regional areas: No states or local agencies 
transfer data. 

How information and data are shared: Application or database sharing
Deployers use the same underlying application to run their 511 systems.
Number of states and metropolitan/regional areas: 9; 
States and metropolitan/regional areas: Eastern Sierra (California), 
Iowa, Kansas, Montana, New Jersey, North Dakota, Rhode Island, South 
Dakota, Vermont. 

Source: GAO analysis of 511 Deployment Coalition data. 

[End of table] 

Private Companies Disseminate Traffic Information through Newer 
Technologies: 

Historically, privately operated news and media outlets have 
disseminated traffic information over radio and television broadcasts. 
In recent years, private companies have begun to disseminate traffic 
information through newer technologies such as cell phones, the 
Internet, and navigation devices in vehicles, among others. 

* The services provided by the companies that use these newer 
technologies include: 

- e-mail and cell phone alerts about traffic congestion and incidents; 

- Web sites that provide various types of traffic information, 
including personalized drive times and live video; and 

- navigation devices (in-vehicle and portable) that can provide 
information on traffic flow and speed, estimated travel times, and lane 
closures, among other things. 

Some private companies disseminate traffic information directly to the 
public. These companies provide basic traffic information to the public 
for free on Web sites and more detailed information for a fee. Some 
private companies provide traffic information to state and local 
agencies or other private companies, which then disseminate this 
information. 

Furthermore, some private companies disseminate traffic information 
nationally, mainly in metropolitan areas. Following are examples: 

* Westwood One disseminates real-time traffic information to the public 
nationwide through its affiliations with 2,400 radio stations, more 
than 170 television stations, and more than 250 Web sites. 

* Clear Channel’s Total Traffic Network disseminates real-time traffic 
data in 95 cities via in-car or portable navigation devices, broadcast 
media, and wireless and Internet-based services. 

* NAVTEQ Traffic is available in more than 120 markets across the 
nation. The company disseminates traffic information to the public 
about road construction, traffic speeds, and incidents through in-
vehicle and personal navigation devices, cell phones, and Web sites. 
NAVTEQ Traffic also provides traffic information to other private 
companies that disseminate information through navigation devices. 

* A number of other companies, such as Google and Yahoo!, disseminate 
real-time traffic information—such as traffic flow and speed—nationally 
via Web sites and other means. 

New Private Sector Data Collection Technologies Are Helping to Expand 
Coverage: 

Private companies are expanding the coverage of information that is 
disseminated by both public and private entities by using new 
technologies to increase the collection of real-time traffic data. 

* Some private companies are using newer technologies, such as vehicle 
probes, to collect real-time data on travel time and speed (see fig. 
3). These companies are collecting data beyond what state and local 
governments collect. For example, INRIX—a company that focuses on 
collecting and aggregating real-time traffic data—collects data using 
commercial fleet vehicle probes and other technologies. An advantage of 
such technologies is that data are collected on arterial roads and 
other roads where there are no fixed collection technologies (such as 
fixed sensors). 

Federal Role: 

DOT is conducting research and development to improve traffic 
information coverage by both the public and private sectors. 

* Through its Safe Trip-21 initiative, DOT—in partnership with state 
and local agencies, the private sector, and academia—is testing the use 
of vehicle probes to generate real-time data and provide travelers with 
current information on traffic congestion, roadway conditions, and 
alternative travel options. Vehicle probes use roaming vehicles and 
portable devices to collect data on travel times and speeds. Vehicle 
probes include cell phones and Global Positioning System (GPS) devices. 
Test sites are being operated in the San Francisco Bay area and in the 
I-95 Corridor along the East Coast. 

* DOT has also conducted some evaluations—such as a recent assessment 
of the current state of traveler information—to help determine what 
activities are needed to make real-time information more accurate and 
complete. 

Figure 3: Vehicle Probe Technology for Collecting Real-Time Traffic 
Data: 

[Refer to PDF for image: illustration] 

Vehicle 1: Wireless signal detected at 8:04:26 a.m. 
Vehicle 2: Wireless signal detected at 8:06:58 a.m. 

Travel distance (2 miles), divided by: Travel time (.042 hours), 
equals: Speed (47.6 MPH). 

Sources: GAO and the I-95 Corridor Coalition. 

[End of figure] 

Public-private partnerships are expanding data that state departments 
of transportation can use in disseminating real-time traffic 
information. For example, the Alabama department of transportation 
purchased data from INRIX on roughly 125 miles of roads in the 
Birmingham area to generate travel times for dynamic message signs, and 
the state plans to expand its contract to cover the entire state. 

Despite Their Advanced Technologies, Private Companies Face Certain 
Limitations in the Coverage and Quality of Data They Collect: 

Private companies face certain limitations in the coverage of data they 
collect. Some examples are as follows: 

* Market disincentives (e.g., little demand for real-time traffic 
information) discourage private companies from collecting data on and 
disseminating information about rural roads and minor arterials. 

* Data collected by vehicle probes in commercial fleets depend on where 
these fleets travel. More specifically, some commercial fleets, such as 
delivery companies and taxicabs, may travel only on assigned routes or 
may not travel on freeways. 

* Some state departments of transportation require that private 
companies pay for access to public data. However, some private 
companies told us that although such data could enhance their coverage, 
they often have chosen not to pay for access because the data are not 
of high enough quality to merit payment. 

The quality of data collected using the newer technologies has the 
following limitations: 

* Data from vehicle probes, such as GPS devices and cell phones, may 
not be collected from enough vehicles to achieve the sample size 
required for accuracy. 

* Some commercial fleets avoid travel during peak periods. As a result, 
probe data collected from these fleets may not accurately reflect 
traffic or travel conditions during peak periods. 

Furthermore, the public sector may not be able to determine the quality 
of real-time traffic information it receives from private companies 
because (1) it may have limited access to the underlying data that is 
collected and aggregated by these companies and (2) the methods these 
companies use to collect and aggregate the data may be proprietary. 

[End of Dissemination and Coverage] 

DOT's Actions: 

SAFETEA-LU Requirements: 

In 2005, Section 1201 of SAFETEA-LU required that the Secretary of 
Transportation establish a program to provide all states the capability 
to: 

* monitor, in real-time, the traffic and travel conditions of major 
highways, and; 

* share that information to facilitate national and regional highway 
traveler information, among other things. 

SAFETEA-LU did not include a deadline for the Secretary to establish 
this program. 

SAFETEA-LU does not provide separate funding to implement this program. 
However, Section 1201 of SAFETEA-LU authorizes states to use their 
annual federal-aid highway funds provided through the Highway Trust 
Fund to fund implementation of this program, as well as other ITS 
projects. 

DOT Has Proposed a Program That Has Potential Benefits, but Some 
Stakeholders Are Concerned about Time Frames and Costs: 

DOT Has Proposed a Program that Aims to Improve Traffic Information 
Coverage, Quality, and Sharing: 

To fulfill requirements in SAFETEA-LU, the Federal Highway 
Administration (FHWA) issued a Notice of Proposed Rulemaking in January 
2009 to establish the Real-Time System Management Information Program. 
[Footnote 18] The proposed rule contains minimum requirements for 
states to make information on traffic and travel conditions available 
through real-time information programs and to share this information. 
[Footnote 19] 

* FHWA currently plans to issue a final rule in February 2010.[Footnote 
20] 

The proposed rule aims to create general uniformity among real-time 
information programs to ensure consistent service to travelers and 
other agencies. It also aims to improve the availability of 
information, which could lead to the dissemination of more information 
to travelers by public agencies and private companies, as well as to 
better traffic control by public agencies, among other things. 

* The proposed rule requires states to make certain information 
available on all interstates[Footnote 21] within 2 years and on 
selected metropolitan-area, noninterstate “routes of significance” 
within 4 years.[Footnote 22] (See table 3.) 

States that do not currently collect this information will have to 
select an approach to achieve compliance from a variety of options, 
including installing data collection technologies or contracting with 
private companies to obtain the data, thus improving real-time traffic 
information coverage. These requirements could also provide a basis for 
the development of a new 511 service in states that do not provide this 
service because they lack sufficient data. 

Table 3: Types of Information Required on Interstate and Selected 
Noninterstates, in Metropolitan and Nonmetropolitan Areas: 

Type of information required: Roadway or lane closures due to 
construction activities; 
Interstates (implement within 2 years): Metropolitan areas: [Check]; 
Interstates (implement within 2 years): Nonmetropolitan areas: [Check]; 
Selected noninterstates (implement within 4 years): Metropolitan areas: 
[Check]; 
Selected noninterstates (implement within 4 years): Nonmetropolitan 
areas: Not required. 

Type of information required: Roadway or lane closures due to traffic 
incidents; 
Interstates (implement within 2 years): Metropolitan areas: [Check]; 
Interstates (implement within 2 years): Nonmetropolitan areas: [Check]; 
Selected noninterstates (implement within 4 years): Metropolitan areas: 
[Check]; 
Selected noninterstates (implement within 4 years): Nonmetropolitan 
areas: Not required. 

Type of information required: Roadway weather conditions; 
Interstates (implement within 2 years): Metropolitan areas: [Check]; 
Interstates (implement within 2 years): Nonmetropolitan areas: [Check]; 
Selected noninterstates (implement within 4 years): Metropolitan areas: 
[Check]; 
Selected noninterstates (implement within 4 years): Nonmetropolitan 
areas: Not required. 

Type of information required: Travel time along highway segments; 
Interstates (implement within 2 years): Metropolitan areas: [Check]; 
Interstates (implement within 2 years): Nonmetropolitan areas: Not 
required; 
Selected noninterstates (implement within 4 years): Metropolitan areas: 
[Check]; 
Selected noninterstates (implement within 4 years): Nonmetropolitan 
areas: Not required. 

Source: GAO analysis of DOT information. 

Note: Metropolitan areas refer to geographic areas with populations 
over 1 million, designated as Metropolitan Statistical Areas by the 
Office of Management and Budget. The proposed rule noted that, as of 
December 31, 2006, 49 metropolitan areas had populations over 1 
million. 

[End of table] 

The proposed rule indicates that all state real-time information 
programs that are funded in whole or in part through the Highway Trust 
Fund would be subject to its requirements and that states would need to 
demonstrate compliance prior to authorization of funds for ITS 
projects. 

* According to FHWA officials, the agency’s division offices, one of 
which is located in each state, will monitor compliance and will work 
closely with any states that are facing challenges and allow them 
flexibility. FHWA plans to provide states with additional guidance to 
help them meet requirements. 

The proposed rule also establishes minimum data quality requirements 
for the information that states are required to make available. 
Specifically, the rule establishes minimum requirements for timeliness, 
availability, and accuracy. (See table 4.) 

* To the extent that states adhere to these requirements, they should 
improve data quality nationwide or at least improve the quality of data 
from those entities that do not already meet those minimum 
requirements. 

Table 4: Timeliness, Availability, and Accuracy Requirements for Real-
Time Traffic Information in Proposed Rule: 

Type of information required: Roadway or lane closures due to 
construction activities; 
Requirements: Timeliness[A] for metropolitan areas: 10 minutes; 
Requirements: Timeliness for nonmetropolitan areas: 20 minutes; 
Requirements: Availability[B]: 90%; 
Requirements: Accuracy[C]: 85%. 

Type of information required: Roadway or lane closures due traffic 
incidents; 
Requirements: Timeliness[A] for metropolitan areas: 10 minutes; 
Requirements: Timeliness for nonmetropolitan areas: 20 minutes; 
Requirements: Availability[B]: 90%; 
Requirements: Accuracy[C]: 85%. 

Type of information required: Roadway weather conditions; 
Requirements: Timeliness[A] for metropolitan areas: 20 minutes; 
Requirements: Timeliness for nonmetropolitan areas: 20 minutes; 
Requirements: Availability[B]: 90%; 
Requirements: Accuracy[C]: 85%. 

Type of information required: Travel time along metropolitan area 
highway segments; 
Requirements: Timeliness[A] for metropolitan areas: 10 minutes; 
Requirements: Timeliness for nonmetropolitan areas: Not required; 
Requirements: Availability[B]: 90%; 
Requirements: Accuracy[C]: 85%. 

Source: DOT. 

[A] Timeliness requirements refer to the time it takes to deliver the 
information. 

[B] Availability requirements refer to the percentage of time that the 
information is expected to be available, at a minimum, based on the 
design of the real-time information program. 

[C] Accuracy requirements refer to the percentage of time that the 
information is expected to be accurate, at a minimum, based on the 
design of the real-time information program. 

[End of table] 

The proposed rule allows states flexibility in how they will meet the 
requirements. 

* There is no requirement for a state or other entity using federal 
funds to apply any particular technology in collecting the data 
necessary to fulfill the program’s specifications. For example, states 
may use their existing fixed sensors to collect data on travel times on 
highway segments. 

* States may use any business approach to establish a real-time 
information program. For example, states can collect data on their own, 
contract with the private sector to collect all or some of the data, or 
purchase information products from the private sector. 

* States can employ any technology for disseminating information. 
States could continue to provide information through 511 services or 
state Web sites. Additionally, FHWA encourages states to partner with 
the private sector to disseminate to the public information that is 
made available under the proposed rule. 

SAFETEA-LU Requirements: 

SAFETEA-LU also required the Secretary of Transportation to establish 
data exchange formats within 2 years of the act’s enactment to 
facilitate the sharing of data on traffic and travel conditions across 
jurisdictional boundaries and the availability of such information 
nationwide. 

SAFETEA-LU further required states to incorporate the data exchange 
formats established by DOT into their traffic and traveler information 
systems but did not specify a deadline for states’ use of these 
formats. 

DOT Has Proposed Guidance on Data Exchange Formats: 

To fulfill SAFETEA-LU requirements, in 2007, FHWA issued interim 
guidance on the use of standard formats for exchanging data on traffic 
and travel conditions. These formats, to the extent that states utilize 
them, allow the data collected by a state to be available to any other 
state or jurisdiction that wants to retrieve the data in the same 
format. FHWA plans to finalize the data exchange format guidance after 
the Real-Time System Management Information Program regulations are 
finalized in early 2010. 

* Once finalized and adopted by states, the guidance would support the 
proposed Real-Time System Management Information Program by making it 
easier for states and jurisdictions to share the basic real-time 
traffic information the program requires. The exchange formats in the 
guidance link the proposed program requirements to specific ITS 
standards for data exchange.[Footnote 23] To the extent that states use 
these formats and incorporate these ITS standards, information will be 
easier to exchange across multiple jurisdictions. 

According to DOT officials, although states are required under SAFETEA-
LU to incorporate the data exchange formats, DOT does not plan to 
require states to use them in the near term because the ITS standards 
on which the formats are based are still under development. 

* DOT officials said that the department could adopt the ITS standards 
referenced in the data exchange format guidance when these standards 
are finalized, and DOT could then require states to use them.[Footnote 
24] However, DOT has no plans to adopt the standards at this time. 

DOT has not obtained information on what data exchange formats states 
use since its 2004 surveys of ITS deployments in large metropolitan 
areas, but agency officials said that they may obtain this information 
in their next ITS deployment survey effort in 2010. Furthermore, 
according to DOT officials, the agency’s division offices will monitor 
how well states are following the data exchange format guidance. 

Stakeholders Have Cited Benefits of the Proposed Program: 

State and local officials,[Footnote 25] as well as private sector 
representatives, have cited a number of potential benefits of the 
program. 

* Most state and local government officials and private sector 
representatives we interviewed said that improved coverage and 
information sharing would provide travelers more information so that 
they have the opportunity to choose the most efficient route to reach 
their destination, thus providing the opportunity to reduce congestion 
and obtain potential benefits to the environment, the economy, and 
disaster evacuation efforts. 

* Some private companies that submitted comments on the proposed rule 
said that the program would advance the data collection market and 
would provide them with additional opportunities to fill gaps in public 
agencies’ data collection. 

State and Local Stakeholders Have Cited Time Frames and Costs as 
Challenges in Implementing the Proposed Program: 

Most state and local government officials that we interviewed cited 
challenges in implementing the program within the specified time frames 
and said that the program would be difficult to implement without 
additional funds. Because some states and local governments are facing 
budget constraints, the implementation of a real-time information 
program may not be a priority. 

According to some state and local transportation agencies that 
submitted comments to the proposed rule, the proposed requirements may 
not take into account local needs and could be challenging to implement 
even for states with existing 511 services. For example, the 
Metropolitan Transportation Commission, which operates San Francisco 
Bay Area’s 511 service, said that there is little need for roadway 
weather information in areas of the country where weather does not 
significantly affect travel. Furthermore, Kansas noted that it would be 
challenging for them to collect certain traffic data, such as on 
incidents in rural areas, because they may have limited or no resources 
or infrastructure in these areas to collect this data and report it to 
their statewide 511 service. 

DOT is currently considering options to address stakeholders’ concerns 
as it finalizes the program’s requirements. We are not making 
recommendations to DOT about the Real-Time System Management 
Information Program at this time because the agency’s efforts to 
establish the program are still in the preliminary stages. 

[End of DOT's Actions] 

Nationwide System: 

Mobility improvements are typically measured in terms of decreases in 
delay and travel time, and improvements to the environment are measured 
by decreases in emissions and fuel consumption. See enclosure II for 
examples of studies that discuss the impact of real-time traffic 
information systems and technologies on mobility and the environment. 

Most Selected Experts Said a Nationwide System Is Needed, but Their 
Visions of Such a System Varied: 

Most Experts Saw a Need for a Nationwide System: 

Seventeen of the 19 experts we interviewed said that a need exists for 
the development of a nationwide real-time traffic information system. 

* Some of these 17 experts noted that current approaches to developing 
real-time traffic information systems are fragmented because state and 
local transportation agencies generally develop and use these systems 
within their own jurisdictions, leading to gaps in coverage and 
inconsistencies in the quality and types of data collected. 

- Many of these experts emphasized that, in their view, information 
coverage would be expanded and data quality improved under the 
nationwide system they envisioned, resulting in benefits for mobility 
and the environment beyond existing real-time traffic information 
systems. 

- Some experts also said that they believe that further enhancements in 
the sharing of information under a nationwide system could provide 
potential benefits to the economy and improve coordination of emergency 
response efforts that might not be realized under existing state or 
regional systems. For example, improved information sharing could allow 
commercial truckers to better plan their interstate trips and, in turn, 
reduce delivery times or make delivery times more reliable. It also 
could allow multijurisdictional areas to communicate better prior to, 
during, and after an emergency. 

Two of the 19 experts we interviewed, however, said that they saw no 
need for the development of a nationwide system. 

* One said that there was no need, in part, because adjoining states or 
jurisdictions that need to share information have already developed 
methods for doing so, such as states that are a part of the I-95 
Corridor Coalition. This expert said that multiple regional systems 
across the nation would be sufficient. 

* The other said the benefits of such a system would not be sufficient 
to justify the level of investment that would be needed to develop it. 

The 17 experts that said there was a need for a nationwide system had 
varying views on the type of nationwide system that is needed (see fig. 
4). 

* Seven of these 17 experts either envisioned a nationwide system that 
would be similar to the anticipated results of current efforts by DOT, 
state and local transportation agencies, and the private sector or said 
that current efforts are already leading to a nationwide system. 

* Ten of these experts envisioned a nationwide system that would go 
beyond current efforts, such as a system creating a national user 
interface for disseminating information, but these visions varied.
•
Some experts said that current efforts are not sufficient to develop a 
nationwide system. For example, one expert noted that DOT’s proposed 
rule on the Real-Time System Management Information Program would 
actually create statewide systems, rather than a nationwide system. 

For the purposes of this review, current efforts that some may see as 
leading to a nationwide real-time traffic information system include: 

* DOT’s efforts to establish the Real-Time System Management 
Information Program; 

* state and local transportation agencies’ efforts to expand coverage 
of 511 Traveler Information Services; and; 

* the private sector’s efforts to collect, aggregate, and disseminate 
real-time traffic information across the nation. 

Most of these 10 experts envisioned little change in the roles of state 
and local transportation agencies—that is, the agencies would continue 
to deploy, or partner with other public agencies or private companies 
to deploy, real-time traffic information technologies that collect, 
aggregate, and disseminate real-time traffic information. 

Figure 4: Views of Experts on Whether a Nationwide Real-Time Traffic 
Information System Is Needed and Whether Such a System Should Go Beyond 
Current Efforts: 

[Refer to PDF for image: illustration] 

19 experts interviewed: 

* 2 saw no need for the development of a nationwide system; 
* 17 saw need for the development of a nationwide system: 
- 7 envisioned a nationwide system similar to results of current 
efforts; 
- 10 envisioned a nationwide system that would go beyond current 
efforts. 

Source: GAO. 

[End of figure] 

DOT is currently developing an ITS strategic plan that will identify 
the direction of the department’s ITS program over the next 5 years. 
DOT has sought stakeholders’ views in developing this plan, including 
views on what its role in real-time traffic information systems should 
be. Some have called for DOT to strengthen its role in this area. For 
example, one stakeholder commented that it is critical for DOT to 
develop a variety of standards and guidelines for data exchange and for 
those standards to be adopted by public and private stakeholders. 

Visions of a Nationwide System beyond Current Efforts Varied: 

The 10 experts that envisioned the development of a nationwide system 
beyond current efforts had varying views on the appropriate level of 
involvement for DOT and the private sector, as well as on the form a 
nationwide system could take. Among the aspects of a nationwide system 
envisioned by these experts are a strong leadership role by DOT, 
increased DOT partnerships with the private sector, and a national 
interface for disseminating information. These differing aspects are 
not necessarily mutually exclusive. For example, DOT could both take a 
strong leadership role and partner with the private sector to collect, 
aggregate, and disseminate real-time traffic information. 

Strong leadership role by DOT—A few experts envisioned that DOT would 
play a strong leadership role in a nationwide system, specifically by 
developing and enforcing requirements and providing funding for state 
and local transportation agencies to develop and maintain real-time 
traffic information systems. 

* Some experts said that DOT should take a strong role in developing 
and enforcing requirements for the types of information to be collected 
and disseminated, data quality, and common data exchange formats, as 
well as ITS standards. For example, by ensuring compliance with its new 
requirements under the Real-Time System Management Information Program, 
DOT could help ensure consistency in the types of information collected 
and in the quality of the data.[Footnote 26] In addition, one expert 
said that DOT’s reluctance to require that states use ITS standards 
will dilute the effectiveness of those standards.[Footnote 27] 

* Although SAFETEA-LU does not provide separate funding for states to 
implement the Real-Time System Management Information Program, several 
experts said additional funding is necessary to develop a nationwide 
system. One expert envisioned DOT as a grant-giver or funder of real-
time traffic information programs. In this vision, by directly funding 
such programs, DOT could better set and enforce requirements that could 
improve data coverage, quality, and sharing. 

* Other experts said that DOT could act more like the operator of a 
nationwide system. For example, DOT could enter into and manage 
agreements with the private sector to collect and disseminate a base 
level of real-time traffic information nationwide. Or DOT could develop 
and operate a national user interface—such as a phone number or 
Internet page—that a traveler, regardless of location, could call or 
access to obtain, or be directed to, relevant information. 

Increased partnerships with the private sector—While some private 
companies currently partner with state and local transportation 
agencies, several experts envisioned a nationwide system that would 
have even more private sector involvement. Some of these experts noted 
that the private sector is using more advanced technology and that a 
nationwide system should take advantage of this innovation. Examples 
are as follows: 

* Two experts envisioned a private company contracted by either DOT or 
state and local transportation agencies. In the first vision, DOT would 
contract with a private company, and the single contract with DOT could 
help ensure the collection of consistent data nationwide. In the second 
vision, which would replicate the I-95 Corridor Coalition’s business 
model on a national level, state and local transportation agencies 
within a region would jointly contract with a single private company to 
collect and aggregate data and translate the data into real-time 
traffic information. The state and local transportation agencies would 
disseminate the information to the public and might also collect and 
disseminate additional information beyond the data provided to the 
region under the private contract. 

* Another expert envisioned that DOT would contract with several 
private companies to collect and aggregate data on behalf of state and 
local transportation agencies. In this vision, the private sector would 
perform most operations needed to support the nationwide system, and 
DOT would establish data quality standards and other specific 
requirements, such as requirements to ensure consistency in the 
information collected and disseminated. Information could be 
disseminated to the public by either or both entities. 

National user interface for disseminating information—While the current 
511 phone number could serve as a national user interface, 511 Traveler 
Information Services are not available in all states, and the various 
state and regional services do not provide consistent information. Two 
experts envisioned a nationwide system—possibly operated by the federal 
government or the private sector—that would disseminate information 
through a public user interface, such as a common phone number or Web 
site. This public user interface would provide consistent information 
and would be accessible to travelers from anywhere in the nation, at 
any time. 

* One expert envisioned a national phone system that would receive 
calls centrally and disseminate information to travelers to allow state 
and local agencies to focus their resources on data collection without 
having to support all the technology required for information 
dissemination. Another expert envisioned multiple national interfaces 
managed by both the public and private sectors. For example, while 
state and local transportation agencies could operate a nationwide user 
interface that would provide a base level of real-time traffic 
information, private companies could operate another national phone 
number, Web site, or other service that would provide more personalized 
traveler information, but might also require that travelers pay a fee 
for that information. A centralized interface could help ensure 
consistency in the types of data collected and in data quality. 

Experts Held Similar Views on Needed Nationwide Coverage: 

Although experts varied in their views on the form a nationwide system 
could take, most said that a nationwide system should, at a minimum, 
cover controlled access roads, such as interstates, in both urban and 
rural areas. These experts also said that the nationwide system should 
cover some key arterial roads. 

* One expert noted that information for every road all the time would 
be ideal but not feasible. 

* Some experts said that while a nationwide system should cover at 
least interstates and other controlled-access roads and some key 
arterial roads, the types of information collected and disseminated 
could vary depending on the characteristics of the road—controlled 
access versus arterial and low volume versus high volume. 

Experts Cited Challenges in Designing and Implementing a Nationwide 
System: 

Some experts predicted that reaching consensus on the form of a 
nationwide system and the roles of the public and private sectors could 
be a major challenge. 

* Some experts noted that state and local transportation agencies 
prefer to maintain control over efforts within their borders. Thus, a 
design that dramatically changed the role or shifted the level of 
control or responsibility from the state and local levels to the 
federal level or to the private sector could meet with resistance from 
states and localities. 

* Some experts noted that difficulties in quantifying the benefits and 
costs of such a system would make it challenging to determine the most 
cost-effective design.[Footnote 28] See enclosure II for results of 
studies that conducted benefit-cost analyses of real-time traffic 
information systems and the challenges in conducting such analyses. 

Experts also cited several potential challenges to implementing a 
nationwide system that they said would need to be addressed. 

* The most common implementation challenge cited by the experts was the 
availability of funding. As previously discussed, some state and local 
agencies are already anticipating significant challenges in 
implementing DOT’s proposed Real-Time System Management Information 
Program because of budget constraints. Any additional modifications, 
such as in the format for collecting data or disseminating information, 
could be a challenge for state or local agencies, given resource 
constraints. 

Other implementation challenges cited by experts included: 

* the need for a clear and sustained vision; 

* the need to ensure consideration of local area needs; 

* limited staff expertise, such as states’ limited knowledge of 
emerging technologies; 

* limited understanding of the data quality needed to provide useful 
information to travelers and of how to measure this quality; and; 

* limited public awareness and use of traffic information.[Footnote 29] 

A few experts noted, however, that resistance to change and funding 
challenges could be minimized if a nationwide system were built on 
existing efforts or systems, such as 511 Traveler Information Services. 
In their view, a nationwide system that significantly changed existing 
efforts or systems would meet with resistance and require more 
resources. 

The above viewpoints may provide information that is useful to 
policymakers as they consider the future direction of federal efforts 
related to real-time traffic information systems. We are not making 
recommendations on this topic at this time, however, because there is 
no clear consensus among the experts we consulted on whether an 
increased federal role in this area is appropriate or what this role 
might be. 

[End of Nationwide System] 

[End of Enclosure I] 

Enclosure II: Impact and Costs: 

We conducted a literature review to identify studies from 2004 onward 
on the impacts (on mobility, the environment, and the economy) and 
costs of real-time traffic information systems and technologies. 
Specifically, we targeted our literature search to a few literature 
databases, including the Transportation Research Information Services 
database—a bibliographic database on transportation issues. We also 
searched DOT’s ITS Benefits and Costs databases, which are publicly 
available. We reviewed the methodologies of studies identified as 
relevant to this report and determined that they were sufficiently 
reliable. See enclosure III for more details on our objectives, scope, 
and methodology. 

In its ITS Benefits and Costs databases, DOT compiles and summarizes 
studies on the benefits and costs of ITS, including real-time traffic 
information systems. In addition to providing summaries of studies, 
DOT’s ITS Costs database also provides information on the capital, 
operations, and maintenance costs associated with individual ITS 
technologies, including those such as video surveillance cameras and 
dynamic message signs that can be used to collect or disseminate 
traffic information. 

Studies Found Positive Impacts of Real-Time Traffic Information Systems 
or Technologies and Identified Costs: 

Studies Found Improvements to Mobility and the Environment, but Results 
Are Not Generalizable: 

Studies we reviewed that quantified the impact of real-time traffic 
information systems or technologies found that these systems or 
technologies improved mobility and the environment.[Footnote 30] Some 
of these studies evaluated real-time traffic information technologies 
specifically, while others evaluated the technologies as part of an 
overall ITS. 

* For example, a study of a traveler information system—consisting of 
various technologies that collect, aggregate, and disseminate 
information on traffic and travel conditions—for a freeway network in 
Los Angeles, California, found that deploying this system decreased 
travel time by up to 14 percent. See table 5 at the end of this 
enclosure for more details on this study, as well as the results of 
other studies we reviewed. 

The quantitative impacts of these studies are not generalizable or 
comparable because these studies are generally specific to a particular 
city or road network and evaluate a specific system or technology. 

Few of the studies we reviewed found negative impacts associated with 
these systems. One study, however, found that traveler information 
systems that recommend alternative routes (such as dynamic message 
signs) may, in some cases, cause congestion on these alternative 
routes. As a result, a traveler may not experience the intended travel 
time reduction. 

No Studies Quantified Impacts on the Economy: 

We did not identify any studies that quantified the impacts of real-
time traffic information systems and technologies on the economy, such 
as on the nation’s gross domestic product (GDP). 

However, to the extent that real-time traffic information systems and 
technologies reduce congestion and improve mobility, there may be 
economic benefits. 

* According to the Texas Transportation Institute, in 2007, the cost of 
congestion to the nation’s urban economy was about $87 billion. 
[Footnote 31] 

Some private sector representatives we interviewed told us that, based 
on their observations, real-time traffic information technologies can 
foster economic expansion by speeding the delivery of people, goods, 
and services. 

Studies Have Found That Costs Vary with a Range of Factors: 

The costs to deploy, operate, and maintain real-time traffic 
information systems and technologies vary based on a range of factors 
including the size, complexity, usage, coverage, and content provided, 
among other things. 

* For example, a case study published by the 511 Deployment Coalition 
in 2006 summarized the costs of six statewide 511 services. Of the 511 
services reviewed, Virginia’s had the largest total cost (about $5.2 
million) and Kansas had the smallest total cost (about 
$990,000).[Footnote 32] See table 5 for examples of other studies that 
documented the costs associated with real-time traffic information 
systems and technologies. 

According to a draft study conducted for DOT, the costs of technologies 
and systems that disseminate real-time traffic information, such as 511 
systems, can be more easily measured and tracked than the costs of 
technologies and systems that collect and aggregate data. 

* The costs of technologies used to collect and aggregate data are more 
difficult to isolate because the infrastructure supports multiple 
operations, including traffic and incident management operations. 

Studies That Conducted Benefit-Cost Analyses Found That Benefits 
Outweighed Costs: 

Of the 20 studies we reviewed, 8 of these studies compared the benefits 
with the costs. 

The 8 studies that included a benefit-cost analysis found that the 
benefits were greater than the costs. See table 5 for examples of 
studies that included benefit-cost analyses. 

* A majority of these 8 studies evaluated real-time traffic information 
technologies as part of a larger system, such as an Intelligent 
Transportation System. 

* One study—DOT’s analysis of the Real-Time System Management 
Information Program—conducted a benefit-cost analysis of a national 
real-time information program.[Footnote 33] As noted previously, this 
program contains minimum requirements for all states to make 
information available on traffic and travel conditions via real-time 
information programs. 

- This study found that the present value of total cost savings (about 
$30.2 billion) due to benefits to mobility, the environment, and safety 
would be greater than the present value of the costs (about $1.2 
billion) to establish and operate the program. See table 5 for more 
details. 

[Side bar: 
Impacts that are simulated use assumptions about traveler behavior. 
However, travelers’ actual responses to information may differ from the 
assumed responses used in the estimate. For example, travelers may 
choose not to change their travel plans despite receiving information 
about heavy congestion. Or, drivers who switch to other modes of 
transportation after receiving information on roadway congestion may 
later decide to switch back to driving on these roadways. End of side 
bar] 

Efforts to Determine Impacts and Conduct Benefit-Cost Analyses Pose 
Challenges and May Have Limitations: 

It is challenging to determine the comprehensive impacts and conduct 
benefit-cost analyses of real-time traffic information systems and 
technologies. Furthermore, although studies quantify benefits 
associated with these systems and technologies, these studies may have 
limitations that affect the certainty of the results. Specifically, 
challenges and limitations exist with capturing data, isolating 
impacts, and simulating impacts. 

* Capturing data. It is challenging to capture data about travelers and 
their responses to real-time information, particularly since some 
travelers may receive information anonymously anywhere, at any time 
(e.g., through the radio or through the Internet). 

* Isolating impacts. It is challenging to isolate the quantitative 
impacts of real-time traveler or traffic information systems because 
external factors can influence evaluation outcomes. As we have 
previously reported, once transportation investments are completed, 
they become part of an entire transportation system and, therefore, the 
effects of the individual project become difficult to isolate, 
evaluate, and attribute to the individual project.[Footnote 34] 

* Simulating impacts. Many of the estimated impacts of real-time 
traffic information systems or technologies are simulated. One 
limitation of using simulation methodologies to quantify impacts is 
that the methodologies depend on simplified assumptions—such as about 
traveler behavior—and therefore, the simulated outcomes may differ from 
actual outcomes. 

DOT Is Considering Research on Impacts and Is Encouraging Benefit-Cost 
Analyses: 

DOT is considering a variety of research programs and activities for 
inclusion in its ITS strategic plan, which it expects to issue in early 
2010. As part of the strategic planning process, DOT has sought input 
from stakeholders on ITS research needs. 

* One stakeholder group, the American Association of State Highway and 
Transportation Officials (AASHTO), noted to DOT that there is a need to 
identify and document the benefits of real-time information for 
mobility and the environment, as well as for safety, particularly since 
collecting and analyzing this information can be costly for most 
states. 

* DOT officials told us that research that addresses mobility impacts, 
or impacts on the environment and the economy, of real-time traffic 
information systems and technologies is being considered for inclusion 
in the strategic plan. 

In response to our 2005 recommendation that DOT encourage cost-
effectiveness analyses, as well as benefit-cost analyses of ITS, 
including real-time traffic information systems,[Footnote 35] DOT has: 

* included benefit-cost analyses of ITS deployments in a database on 
ITS benefits that DOT makes available on its Web site, and; 

* promoted a software program—in a guide on resources and tools for 
state and local planners—that can be used to evaluate the benefits and 
costs associated with ITS investments, including real-time traffic 
information systems and technologies. 

Table 5: Examples of Studies That Quantified Benefits of Real-Time 
Traffic Information Programs, Systems, or Technologies; Identified 
Costs; or Conducted Benefit-Cost Analyses: 

City or road network evaluated/year study published: Road network in 
Irvine, California; 2004; 
Program, system, or technology evaluated: Traveler information system
Benefits: Mobility; Savings in travel time of around 5 percent during 
morning peak hours (5:45 a.m. to 10 a.m.), assuming that 15 to 20 
percent of travelers followed instructions of the traveler information 
system. Decrease in the average time to clear incidents by 7 minutes, 
based on historical data.
Costs: Information not available.
Benefit-cost analysis: Information not available. 

City or road network evaluated/year study published: Freeway network in 
Los Angeles, California; 2006; 
Program, system, or technology evaluated: Traveler information system
Benefits: Mobility; Savings in travel time of up to 14 percent. Travel 
time savings were larger during the evening peak hours (4:00 p.m. to 
7:00 p.m.). Decrease in travel time variability of up to 50 percent, 
depending on the type of information.
Costs: Information not available.
Benefit-cost analysis: Information not available. 

City or road network evaluated/year study published: A construction 
work zone on an Interstate in Devore, California; 2006; 
Program, system, or technology evaluated: Sensor to collect travel time 
data, software to estimate travel time, dynamic message signs, and a 
Web site; 
Benefits: Mobility; Decreased traffic volumes during weekday peak-hour 
traffic in the work zone, causing a reduction in traffic delay from an 
expected 90 minutes to an actual 50 minutes. Traffic volumes on 
neighboring freeways increased but the increase in travel time on these 
roads was insubstantial. 
Costs: The total cost of leasing and maintaining the technologies and 
of analyzing the data was about $0.2 million.
Benefit-cost analysis: See table note below. 

City or road network evaluated/year study published: Arizona, North 
Carolina, Utah, Virginia, Kansas, and Washington; 2006; 
Program, system, or technology evaluated: Statewide 511 services
Benefits: Information not available.
Costs: On average, the statewide 511 services cost $2.5 million to 
design, implement, and operate and maintain for 1 year. Virginia had 
the largest total cost (about $5.2 million), and Kansas had the 
smallest total cost (about $990,000).
Benefit-cost analysis: Information not available. 

City or road network evaluated/year study published: U.S. highway in a 
rural area north of Spokane, Washington; 2004; 
Program, system, or technology evaluated: Environmental sensor stations 
that collect and transmit road weather data, video surveillance 
cameras, and Highway Advisory Radio; 
Benefits: Information not available.
Costs: The total cost to construct and install these technologies was 
$446,807.
Benefit-cost analysis: Information not available. 

City or road network evaluated/year study published: Tucson, Arizona; 
2005; (a forecast for the year 2025)[A]; 
Program, system, or technology evaluated: ITS—consisting of 35 
technologies including Highway Advisory Radio, dynamic message signs, a 
telephone- and Web-based traveler information system, and kiosks.
Benefits: Mobility; Expected decrease in delay due to recurring 
congestion by about 6 percent, expected decrease in incident-related 
delay by more than 70 percent on freeways, and expected decrease in 
annual travel time by 7 hours per resident.
Environment; Expected reduction in annual fuel use by 11 percent and 
expected reduction in annual carbon monoxide, hydrocarbon, and nitrous 
oxide emissions between 10 and 16 percent.
Costs: The expected average annual cost for implementing, operating, 
and maintaining all 35 ITS technologies was about $72 million. More 
specifically, the expected annual cost for implementing, operating, and 
maintaining the regional telephone- and Web-based traveler information 
system and 5 kiosks was $2.1 million.
Benefit-cost analysis: The expected average annual benefit of the ITS 
to mobility, the environment, safety, and other areas ($455 million) 
was greater than the expected average annual cost to implement, 
operate, and maintain the ITS. The benefits outweighed the costs by a 
ratio of 6.3 to 1. 

City or road network evaluated/year study published: Nationwide; 2009
Program, system, or technology evaluated: Real-Time System Management 
Information Program; 
Benefits: Mobility; Savings in incident delays of about 321 million 
hours, annually.
Environment; Reduced annual hydrocarbon and nitrous oxide emissions by 
about 8,200 tons and 11,600 tons, respectively. Reduced annual gasoline 
use by about 447 million gallons.
Costs: The present value of the total cost for establishing real-time 
information programs in all states and the nation’s 50 largest 
metropolitan areas and operating these programs through 2018 would be 
about $1.2 billion.
Benefit-cost analysis: The present value of total cost savings (about 
$30.2 billion) due to benefits to mobility, the environment, and safety 
would be greater than the present value of the costs to establish and 
operate the program. Specifically, the present value of the benefits 
would exceed the present value of the costs by about $29 billion 
through 2018. 

Source: GAO analysis of select studies. 

Note: Dollar figures are in current dollars, not adjusted for 
inflation. The study in Devore, California, found that the net benefit 
of implementing the technologies during 18 days of closures due to 
construction was estimated to be about $3.6 million. However, we could 
not confirm the reliability of this estimate. 

[A] This study forecasted the impact of ITS technologies on mobility, 
the environment, and other areas in 2025 based on traffic forecasts and 
planned ITS deployments for that year. 

[End of table] 

[End of Enclosure II] 

Enclosure III: Objectives, Scope, and Methodology: 

Objectives: 

The objectives of this report were to determine (1) how state and local 
agencies and the private sector disseminate real-time traffic 
information to the public, and the completeness of current coverage; 
(2) what actions DOT has taken to establish the Real-Time System 
Management Information Program required by the Safe, Accountable, 
Flexible, Efficient Transportation Equity Act: A Legacy for Users 
(SAFETEA-LU), and stakeholders’ views on these actions; and (3) how 
selected experts view the need for and benefits of a nationwide real-
time traffic information system, how they envision such a system, and 
what the related challenges may be. We also examined what studies have 
found about the impacts of real-time traffic information systems and 
technologies—particularly on mobility, the environment, and the economy—
and their costs. 

Scope: 

This report focuses on real-time traffic information that is 
disseminated to the public. Real-time traffic information that is used 
for traffic management purposes is not in the scope of this report. 

Methodology: 

To determine how state and local agencies and the private sector 
disseminate real-time traffic information to the public and the 
completeness of current coverage, we interviewed—and reviewed relevant 
reports and studies obtained from—DOT officials; representatives from 
national organizations involved in real-time traffic information 
initiatives, such as the American Association of State Highway and 
Transportation Officials (AASHTO) and the Intelligent Transportation 
Society of America (ITS America); state and local transportation 
officials; and four private companies involved in real-time traffic 
information initiatives. More specifically, we interviewed state and 
local officials during site visits in California and Florida. We 
selected these locations for site visits because they have well-
developed real-time traffic information systems, have deployed a range 
of technologies to collect and disseminate real-time traffic 
information, have 511 Traveler Information Services, and have differing 
public-private partnership models for collecting, aggregating, and 
disseminating real-time traffic information. Furthermore, officials 
from DOT, and representatives from AASHTO and ITS America, suggested 
that we visit these locations. The four private companies that we 
interviewed collect, aggregate, and disseminate real-time traffic 
information. To identify these companies, we obtained recommendations 
from DOT, AASHTO, and ITS America as to which companies play key roles 
in those areas. 

We also reviewed and analyzed survey data from DOT’s ITS Deployment 
Tracking Database for 2007, the most recent survey year. This database 
contains state and local agencies’ responses to multiple surveys on the 
deployment of various ITS technologies, including real-time traffic 
information technologies, in the nation’s 108 largest metropolitan 
areas. The metropolitan areas selected are those that have populations 
of more than 50,000. We focused our review on agency responses to two 
surveys--one on the deployment of ITS technologies on freeways and the 
other on ITS deployments on arterial roads. Nearly all metropolitan 
areas responded to both the surveys. We used the survey data in the 
database to determine the types of technologies and systems in use and 
their coverage. Based on interviews with DOT officials and our analysis 
of the data, we determined that the data were sufficiently reliable for 
the purposes of this report, which was to provide (1) general 
information on the types of technologies and systems used to collect 
and disseminate real-time traffic information to the public and (2) 
general estimates of the coverage of these technologies, including the 
number of metropolitan areas in which incident, travel time, and travel 
speed information were disseminated to the public in 2007. 

To determine what actions DOT has taken to establish the Real-Time 
System Management Information Program, we reviewed and analyzed Section 
1201 of the 2005 transportation authorization—SAFETEA-LU—which made DOT 
responsible for establishing the program. We also interviewed DOT 
officials on their actions to establish the program, and reviewed and 
analyzed the proposed rule and related guidance that DOT published in 
the Federal Register. To determine stakeholders’ views on the expected 
benefits and challenges to implementing the proposed program, we 
interviewed selected state and local transportation officials and 
representatives of AASHTO and two private companies that provide real-
time traffic data. The state and local officials we interviewed on this 
issue were those that we met with during our site visits and those 
selected by the National Academy of Sciences (NAS). Later in this 
section we provide further details on how NAS selected state and local 
government officials and other stakeholders. The private companies we 
interviewed were those identified as key data providers by our own work 
and NAS. To further identify expected benefits of, and challenges to 
implementing the program, we reviewed and analyzed comments that state 
and local agencies, private companies, and organizations submitted to 
DOT in response to the proposed rule and related guidance that DOT 
published in the Federal Register. 

To determine experts’ views on a nationwide system, we conducted 
semistructured interviews with—and reviewed relevant documentation from—
19 experts about options for implementing a nationwide real-time 
traffic information system, including the need for, potential benefits 
of, and challenges to implementing such a system.[Footnote 36] The 
individuals we interviewed from state and local transportation 
agencies, academia, and the private sector (consultants and data 
providers) were selected by NAS. NAS selected these experts based on 
geographic diversity and their knowledge of various aspects of real-
time traffic information systems and technologies, including the roles 
of the federal, state, and local governments and the private sector; 
key technologies used in collecting, aggregating, and disseminating 
traffic information to the public; various models for providing traffic 
information services; and current efforts to implement a nationwide 
real-time traffic information system. We identified three officials 
from DOT as experts because these individuals work on issues, policies, 
and regulations related to real-time traveler or traffic information 
and were identified by DOT as points of contact in these areas. The 19 
experts we interviewed and their affiliations are listed in table 6. 

Table 6: Names of Experts We Interviewed and Their Affiliations: 

DOT: 
Jane Lappin, Volpe National Transportation Systems Center; 
James Pol, ITS Joint Program Office; 
Robert Rupert, Federal Highway Administration. 

State level associations: 
George Schoener, I-95 Corridor Coalition; 
James Wright, American Association of State Highway and Transportation 
Officials (AASHTO). 

State Departments of Transportation: 
Anthony Bradford, Georgia Department of Transportation; 
David Huft, South Dakota Department of Transportation; 
Greg Krueger, Michigan Department of Transportation; 
David Lively, California Department of Transportation. 

Local transportation agencies: 
Matt Edelman, Transportation Operations Coordinating Committee 
(TRANSCOM); 
David Fink, Houston TransStar; 
Carol Kuester, Metropolitan Transportation Commission. 

Academia: 
Mark Hallenbeck, Washington State Transportation Center; 
Christopher Poe, Texas Transportation Institute; 
Philip J. Tarnoff, University of Maryland. 

Private industry (consultants): 
Dean Deeter, Athey Creek Consultants; 
Les Jacobson, Telvent Farradyne Inc. 

Private industry (data providers): 
John Collins, Transportation Business Law and Strategy (formerly with 
NAVTEQ Traffic); 
Rick Shuman, INRIX. 

Source: GAO. 

[End of table] 

Other Aspects of Our Work: 

To describe what studies have found about the impacts (on mobility, the 
environment, and the economy) and costs of real-time traffic 
information technologies and systems, we conducted a literature review 
to identify pertinent studies. Specifically, we targeted our literature 
search to the Transportation Research Information Services database—a 
bibliographic database on transportation issues—and DOT’s ITS Benefits 
and Costs databases. Our search of these databases did not yield 
studies on the impacts of real-time traffic information systems and 
technologies on the economy. Therefore, we extended our literature 
search to additional databases, including the EconLit bibliographic 
database—a database in the field of economics—and the ProQuest and 
WorldCat databases. Our literature search covered studies published 
from 2004 onward. 

Through the literature search, we identified a number of studies that 
discussed technologies and systems that disseminate, or support the 
dissemination of, real-time traffic information to the public. We 
further limited our review to studies that evaluated real-time traffic 
information technologies and systems in the United States and that (1) 
quantified the impacts of real-time traffic information technologies 
and systems on mobility, the environment, or the economy; (2) 
identified the costs of these systems or technologies; or (3) conducted 
benefit-cost analyses. Based on these criteria, we identified a total 
of 20 studies that were relevant and applicable to our report. We 
reviewed the methodologies of these studies to ensure that they were 
sound and determined that they were sufficiently reliable for 
describing the impacts and costs of real-time traffic information 
systems and technologies.[Footnote 37] 

We conducted this performance audit from January 2009 to November 2009, 
in accordance with generally accepted government auditing standards. 
Those standards require that we plan and perform the audit to obtain 
sufficient, appropriate evidence to provide a reasonable basis for our 
findings and conclusions based on our audit objectives. We believe the 
evidence obtained provides a reasonable basis for our findings and 
conclusions based on our audit objectives. 

[End of Enclosure III] 

Enclosure IV: GAO Contact and Staff Acknowledgments: 

GAO Contact: 

David J. Wise, (202) 512–2834, or wised@gao.gov. 

Staff Acknowledgments: 

In addition to the contact named above, Judy Guilliams-Tapia, Assistant 
Director; Lauren Akers; Dwayne Curry; Roshni Davé; Bess Eisenstadt; 
Kathleen Gilhooly; Brandon Haller; Terence Lam; Kirsten Lauber; Ashley 
McCall; Josh Ormond; Madhav Panwar; and Gretchen Snoey made key 
contributions to this report. 

[End of Enclosure IV] 

Footnotes: 

[1] David Schrank and Tim Lomax, 2009 Urban Mobility Report (College 
Station, Texas: Texas Transportation Institute, 2009). 

[2] "Real-time" is a relative measure. Information delivery times 
generally range between 10 and 20 minutes. 

[3] In 2005, SAFETEA-LU authorized funding for federal surface 
transportation programs for highways, highway safety, and transit. See 
Pub. L. No. 109-59, 119 Stat. 1144. Section 1201 of SAFETEA-LU 
established the Real-Time System Management Information Program but did 
not provide separate funding to implement this program. Section 1201 of 
SAFETEA-LU authorizes states to use their federal-aid highway funding 
for efforts related to this program. 

[4] Real-time traffic information can also be used for a range of 
traffic management purposes. For example, traffic managers can use this 
information to control traffic through signal timing, detect traffic 
incidents, and monitor congestion trends. However, traffic management 
is not in the scope of this review. 

[5] We selected the four private companies to interview because they 
were identified by DOT, the American Association of State Highway and 
Transportation Officials, and the Intelligent Transportation Society of 
America as key companies involved in real-time traffic information 
collection, aggregation, and dissemination. 

[6] We interviewed state and local officials in California and Florida 
because, among other reasons, they have well-developed real-time 
traffic information systems and have deployed a range of technologies 
to collect and disseminate real-time traffic information. 

[7] ITS consists of a range of communications, electronics, and 
computer technologies--including those that collect, aggregate and 
translate, and disseminate real-time traffic information--that are 
designed to improve traffic flow and safety. DOT's ITS deployment 
surveys sought responses from state and local agencies to questions on 
the deployment of various ITS technologies, including real-time traffic 
information technologies, in 108 large metropolitan areas. The 
metropolitan areas selected are those that have populations of more 
than 50,000. The most recent surveys were conducted in 2007. We 
reviewed the reliability of the survey data and determined that the 
data were sufficiently reliable for the purposes of this report. See 
enclosure III for more details on our methodology. 

[8] The state and local officials we interviewed included those we met 
with during our site visits and those the National Academy of Sciences 
identified as experts in the areas covered by our third objective. The 
private companies we interviewed were those identified as key data 
providers by the academy, as well as through our own work. 

[9] ITS technologies can also be used for improving safety and for 
transit management. In 2005, we issued a report on the extent to which 
ITS is used as a tool to reduce congestion. See GAO, Highway 
Congestion: Intelligent Transportation Systems' Promise for Managing 
Congestion Falls Short, and DOT Could Better Facilitate Their Strategic 
Use, [hyperlink, http://www.gao.gov/products/GAO-05-943] (Washington, 
D.C.: Sept. 14, 2005). 

[10] Some local agencies have agreements with their respective state 
departments of transportation to collect, aggregate, and disseminate 
real-time traffic information to the public. Some state and local 
agencies also contract with private companies to conduct such 
activities. 

[11] Public agencies also use real-time traffic information for traffic 
management. 

[12] The potential for drivers using cell phones and in-vehicle 
technologies to become distracted has become a major safety concern. 
Some states have banned or restricted the use of cell phones while 
driving. In 2008, GAO addressed safety concerns associated with cell 
phones and in-vehicle technologies in its report, Highway Safety: 
Foresight Issues Challenge DOT's Efforts to Assess and Respond to New 
Technology-Based Trends, [hyperlink, 
http://www.gao.gov/products/GAO-09-56] (Washington, D.C.: Oct. 3, 
2008). However, the impacts of these technologies on safety are not 
within the scope of this review. 

[13] Similar nationwide usage information is not available for 511 Web 
sites because this usage is not tracked consistently by DOT, states, or 
metropolitan areas. 

[14] These surveys reflect ITS deployments by state and local agencies, 
not deployments by private companies. DOT plans to conduct the next 
survey of ITS deployments in 2010. 

[15] These technologies may have provided additional types of 
information, but DOT’s surveys asked only about incidents, travel 
times, and travel speeds. 

[16] According to DOT officials, the term "freeways," which is used in 
its ITS deployment surveys, refers to controlled access roads that have 
no intersections. Arterial roads generally consist of roads that have 
signalized intersections. 

[17] While 94 metropolitan areas responded to the 2007 survey on 
freeway management, 30 of these metropolitan areas did not report 
information on technologies for collecting real-time traffic data on 
their freeways. 

[18] See 74 Fed. Reg. 1993 (Jan. 14, 2009). 

[19] According to DOT’s benefit-cost analysis of the Real-Time System 
Management Information Program, the present value of the total cost for 
establishing real-time information programs in all states and the 
nation’s 50 largest metropolitan areas and operating these programs 
through 2018 would be about $1.2 billion. See enclosure II for more 
details on this analysis. 

[20] Before the rule is finalized, it will have to be reviewed by the 
Office of the Secretary at DOT and by the Office of Management and 
Budget. 

[21] Interstate highways are routes designated as part of the Dwight D. 
Eisenhower National System of Interstate and Defense Highways. 

[22] The proposed rule notes that states should select routes of 
significance based on various factors, including their importance for 
congestion relief, disaster evacuation, economic growth, and safety. 

[23] ITS standards define how ITS systems, products, and components can 
be interconnected and exchange information, among other things. Many 
ITS standards are consensus-based, meaning that all interested parties 
agreed, through cooperation and compromise, on the published standard. 

[24] 23 C.F.R. § 940.11(f) requires that all ITS projects funded 
through the Highway Trust Fund use applicable DOT-adopted ITS 
standards. For DOT to adopt ITS standards, it must first issue a rule, 
but it has not yet done so for any of these standards. 

[25] Some local agencies have agreements with their respective state 
departments of transportation to collect, aggregate, and disseminate 
real-time traffic information to the public. Under such agreements, 
some local governments may support the state departments in 
implementing the requirements of the Real-Time System Management 
Information Program. 

[26] The proposed rule states that FHWA will monitor compliance and may 
decline to approve federal-aid projects, pursuant to 23 C.F.R. § 1.36, 
if a state does not comply with the regulations. 

[27] DOT, through cooperative agreements with six standards development 
organizations such as the Institute of Transportation Engineers, helps 
to develop nonproprietary, industry-based, consensus ITS standards. As 
noted previously, DOT may adopt ITS standards and require states to 
follow them by issuing a rule, but DOT has not yet done so. 

[28] If DOT were to issue a rule on a nationwide real-time traffic 
information system, a regulatory benefit-cost analysis could be 
required to comply with Executive Order 12866 and the Unfunded Mandates 
Reform Act of 1995. Executive Order 12866 directs agencies to conduct 
economic analyses of significant regulatory actions and to select the 
policy that maximizes net benefits to society unless a statute requires 
otherwise. The Unfunded Mandates Reform Act of 1995 requires agencies 
to choose the least costly, most cost-effective, or least burdensome 
option, unless inconsistent with law or the agency head explains why 
this option was not adopted. 

[29] Some of these challenges currently exist for real-time traffic 
information systems and could continue to be challenges for a 
nationwide system. 

[30] Mobility improvements are typically measured in terms of decreased 
delay and travel time, and environmental improvements are measured by 
decreased emissions and fuel use. 

[31] Schrank and Lomax. 

[32] The costs of the two services varied because Virginia’s 511 
service covered many roads within the state, and because the state 
collected data and ensured data quality 7 days a week. By contrast, 
Kansas’ 511 service shared infrastructure with several other states, 
which may have contributed to its lower cost. 

[33] DOT prepared a benefit-cost analysis of the Real-Time System 
Management Information Program to satisfy Executive Order No. 12866 and 
the Unfunded Mandates Reform Act of 1995. 

[34] GAO, Highways and Transit Investment: Options for Improving 
Information on Projects’ Benefits and Costs and Increasing 
Accountability for Results, [hyperlink, 
http://www.gao.gov/products/GAO-05-172] (Washington, D.C.: Jan. 24, 
2005). 

[35] [hyperlink, http://www.gao.gov/products/GAO-05-943]. 

[36] We did not evaluate the experts' options for a nationwide system, 
including factors such as the feasibility and implementation costs 
associated with these options. 

[37] Dollar figures used to describe the costs or cost savings of real-
time traffic information systems and technologies are in current 
dollars, not adjusted for inflation. 

[End of section] 

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