National Traffic Signal Report Card: Highlights, The

Institute of Transportation Engineers. ITE Journal, Jun 2005

THE FIRST-EVER NATIONAL TRAFFIC SIGNAL REPORT CARD IS THE RESULT OF A PARTNERSHIP BETWEEN SEVERAL NTOC ASSOCIATIONS LED BY ITE, THE AMERICAN ASSOCIATION OF STATE HIGHWAY AND TRANSPORTATION OFFICIALS, THE AMERICAN PUBLIC WORKS ASSOCIATION, ITS AMERICA AND THE FEDERAL HIGHWAY ADMINISTRATION.

ON APRIL 20, 2005, THE NATIONAL Transportation Operations Coalition (NTOC) released the first-ever National Traffic Signal Report Card. The report card is the result of a partnership between several NTOC associations led by ITE, the American Association of State Highway and Transportation Officials, the American Public Works Association, ITS America and the Federal Highway Administration.

The results of the report card are documented in the Executive Summary and Technical Report, which both are available on the ITE Web site or through the ITE Bookstore. This feature summarizes the results contained in the Technical Report and from the media effort.

PURPOSE AND BACKGROUND

The purpose of the National Traffic Signal Report Card is to:

* Assess the current state of traffic signal operations in the United States;

* Bring attention to the current state of signal operations;

* Create awareness of the congestion-reducing benefits of good traffic signal operations; and

* Make a case for additional investment in traffic signal operations.

To determine the current state of traffic signal operations in the United States, a self-assessment tool was created. The self-assessment tool was developed by a team of professionals representing NTOC and served as a basis for collecting information and assessing traffic signal systems across the country. This tool was made available to state and local agencies and served an additional purpose of giving agencies a way to benchmark their own performance.

A total of 378 tespondents fully completed the self-assessment. The number of signals represented by the responding agencies correspond to about one-third of all signals in the United States. Table 1 shows the number of responses by agency type and signal system size, respectively.

OVERALL NATIONAL RESULT: D-

The report card includes six sections on topics considered critical to ensuring good traffic signal operations:

1. Proactive management;

2. Coordinated systems;

3. Individual intersections;

4. Specialized operations;

5. Detection; and

6. Maintenance. -

Although information regarding specialized operations was included in the self-assessment, scores for that section are not included in the figures or in the overall total due to the small number of responses and the uniqueness of this category. The national results are shown in Figure 1.

Figure 2 represents the results by signal system size-the number of traffic signals managed by a responding agency. Figure 3 represents the results by agency type-state, county, city and township.

Noteworthy Findings

The overall national score was 62.

* Overall, the scores are low. This should not be a surprise to most traffic engineering professionals. Traffic engineers have known for years that resource constraints prevent the use of traffic signals to their full potential.

* The scores are remarkably similar across the United States and across jurisdictions. Although there may be some high-performing signal systens, on the whole, the vast majority of systems across the country have the potential for greatly improved performance.

* Individualized intersections is the highest scoring section, regardless of the size of the signal system or the agency. At first glance, this is surprising. Particularly for larger systems, the coordinated operations section would be expected to receive the most attention because signal coordination is a highly effective method for improving the performance of the transportation system and reducing delay. However, after further consideration and analysis of responses throughout the self-assessment, it appears that in situations of limited resources and staff, agencies are forced to address problems as they occur at individual intersections. This reflects a reactive approach to managing signal systems that is necessitated due to limited resources. In short, agencies are forced into a "firefighting" mode of operations rather than the preferable proactive management role.

* Another surprise is the comparatively high score in the maintenance section. This is historically an area that struggles to obtain adequate resources, but it scored second only to individualized intersections. Again, reflecting on the analysis further, it becomes clear that for safety and liability reasons, agencies must ensure a basic level of operation so that signals continue to turn green, yellow and red. The signals may not function efficiently for traffic or pedestrians but, technically, the signals are working and that is what people see. However, the uniformly low scores indicate that, for the most part, people consistently experience poor traffic signal performance. The pattern, once again, is one of agencies forced to use their resources to deal with critical maintenance issues when they arise rather than proactively. Their signal systems are managed simply to ensure base levels of performance.