Transportation Infrastructure:

Benefits of Traffic Control Signal Systems Are Not Being Fully Realized

RCED-94-105: Published: Mar 30, 1994. Publicly Released: May 2, 1994.

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Pursuant to a congressional request, GAO reviewed federal, state, and local efforts to use traffic control signal systems to reduce congestion, focusing on: (1) the benefits of traffic control signal systems; (2) the problems state and local agencies face in implementing, operating, and maintaining effective signal systems; (3) the relationship between current signal systems and emerging technologies; and (4) Federal Highway Administration (FHwA) efforts to assist state and local governments' development of traffic signal systems.

GAO found that: (1) state, local, and transportation industry studies have shown that upgrading traffic control signals and changing traffic signal timing can reduce local accidents, congestion, travel time, fuel consumption, and air pollutants; (2) states and localities have experienced problems with traffic signal effectiveness because they have not properly designed, operated, and maintained their signal systems; (3) of the 24 systems FHwA reviewed, 21 did not meet minimum performance standards and some localities were designing outdated systems; (4) in 1989, 74 percent of urban signalized intersections needed upgraded physical equipment or improved signal timing; (5) state and local governments often lack sufficient resources to operate and maintain their signal systems; (6) older signal systems do not provide sufficient traffic volume and flow data needed to support emerging traffic signal technology development; (7) the benefits from emerging technologies may not be realized if states or localities continue to experience operating and maintenance problems and resource constraints; (8) FHwA does not consistently review state and local governments' traffic signal operating plans and it does not have sufficient technical expertise to assist state and local governments with their traffic control signal systems; and (9) FHwA needs to clarify the role of its field offices, issue guidance on preparing operations plans, and develop the necessary expertise to assess the current and future benefits of existing and emerging traffic control signal systems.

Recommendations for Executive Action

  1. Status: Closed - Implemented

    Comments: The Department concurred with the recommendation and stated that FHwA provides oversight and assistance in critical areas and will assist states and localities when requested to the extent possible within FHwA's available resources.

    Recommendation: To better assist states and localities in designing, implementing, operating, and maintaining traffic control signal systems, the Secretary of Transportation should direct the Administrator, FHwA, to identify critical activities in relation to signal systems that require the agency's oversight and assistance.

    Agency Affected: Department of Transportation

  2. Status: Closed - Implemented

    Comments: The Department stated that it recognizes the need to expand its expertise. To accomplish this, FHwA said it has ongoing training programs which provide information regarding systems design, selection, and operations. Through this continuing effort, FHwA is seeking to expand the level of expertise in traffic management among its field personnel. No specific additional FHwA actions resulted from this recommendation, therefore it is being closed.

    Recommendation: To better assist states and localities in designing, implementing, operating, and maintaining traffic control signal systems, the Secretary of Transportation should direct the Administrator, FHwA, to develop the expertise needed to carry out this role and assist the states and localities with their traffic control signal systems.

    Agency Affected: Department of Transportation

  3. Status: Closed - Implemented

    Comments: FHwA issued new guidance in December 1994 that provides information to guide localities in planning for traffic signal systems' long-range resource requirements. The new guidance also strengthens and clarifies FHwA's review requirements.

    Recommendation: To better assist states and localities in designing, implementing, operating, and maintaining traffic control signal systems, the Secretary of Transportation should direct the Administrator, FHwA, to develop guidance for its field offices defining the conditions under which operations plans are required, the content of operations plans (particularly their provisions for the systems' long-range resource requirements), and the review that field offices are to undertake to ensure that the plans are adequately prepared.

    Agency Affected: Department of Transportation

 

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