Arterial Management Program

Improving Traffic Signal Management and Operations: A Basic Service Model

I. Background

Through the 1950's and 1960's, the technology and novelty of automatically controlled traffic signals led the agencies that owned and operated them to develop extensive staff capabilities to support their effective operation. Considerable resources were devoted to the development of guidelines and underlying research, leading to the common result that agency professionals held a high level of expertise and esteem within their agencies.

As traffic signals have become ubiquitous, their operation and management has emerged from a novel program receiving special emphasis to what appears to be a commodity. Agency professionals are less likely to be nationally known experts, less likely to be sent to national conferences where they can learn from their peers, less likely to be supported with society memberships such as in the Institute of Transportation Engineers, and less likely to have direct access to and the unconditional respect of policy makers and elected officials. This trend has led to a feeling of embattlement on the part of highly competent agency professionals, who are asked and sometimes demanded to do more with less as a matter of routine. The frequently seen turnover of elected and policy officials masks the effects of increasing demands even as such demands lead to a breakdown of agency effectiveness. This decline in agency regard mirrors the decline in other infrastructure-support elements within state and local governments.

Professional groups, both organized and ad hoc, have discussed these issues at length, and many methods have been proposed and attempted to bring greater public emphasis to the problem of declining support for traffic signal operation. In all cases, these efforts are hampered by the inability to easily measure the performance of the signal operation, lack of clarity as to the objective of the signal operation, and a simple understanding of how to achieve those objectives. Without clear goals and an equally clear plan to achieve those goals, agency professionals find it more and more difficult to articulate their resource needs within their agencies; even those needs critical to providing good basic service, let alone advanced capabilities. The various facets of this generalized characterization are vast. And despite that the characterization is a generalization, all agency professionals feel the pressure of trying to maintain good basic service in light of declining resources and credibility.

These trends have coupled with increasing urban populations and resulting increases in traffic congestion, which has undermined faith in the ability of traffic engineers to achieve real improvements. Agency professionals are often left with a losing proposition—to try to minimize the rate at which traffic conditions worsen, both as a result of increased demand and as a result of reduced field equipment maintenance.

The FHWA has the difficult task of supporting state and local agencies in their attempts to improve their ability to achieve better results. The reasons for this difficulty can be summarized as follows:

  1. There is no consistent and defensible standard of good operation.
  2. Measuring performance to test against a standard often requires unattainable resources.
  3. As resources have declined, so have the ability of agencies to attract, develop, and retain true experts.
  4. Many agencies depend on consultants to fill their expertise gap, but the turnover of consultants available to do such work is at least as high as the turnover within the agencies. This undermines attempts to improve the competence of practitioners through federally sponsored training, for example. The pool of consultant engineers with no agency experience continues to grow, in many cases widening the expertise gap.
  5. Without a definition of good operation, there is no standard of good maintenance that is generally enforced.
  6. Clear objectives and plans to achieve those objectives are not technical problems, yet the research community often focuses on technical issues, sometimes at levels far beyond the daily reality of practitioners. Research often focuses on technology to provide the solution, with many researchers believing that the hopelessness of developing proper standards and resources requires that meeting such standards will depend on expertise built into automated systems.
  7. Practitioners often have difficulty providing agency policy makers and elected officials with a clear view of progress towards operational goals, and therefore are leaving them with a reluctance to fund improvements. Often practitioners who should provide this clarity feed the problem by not effectively managing expectations or by over-promising results in support of their projects. The classic example is the defense of traffic signal systems on the basis of performance measures wholly related to improved timings, without the recognition that improved timings can be implemented without the system. Thus, systems are not justified by the true needs, which are based on managing field infrastructure as opposed to attaining specific traffic performance improvements.

The FHWA has promoted a number of efforts designed to measure and improve the situation. The Traffic Signal Report Card, which was conducted by the industry in support of a major FHWA initiative, showed generally poor results around the country. But those results were often based on effecting positive outcomes by completing a variety of activities, or by maintaining arbitrary ratios such as the frequency with which signals are retimed or the number of maintenance technicians on staff.

FHWA also has supported the development of a range of training programs, including National Highway Institute courses on computerized traffic signal systems and on traffic signal design and operation, and on Internet-based courses such as on traffic signal timing. These courses help, but they must be part of an overall program to evaluate, reward, and maintain the professional capacity of agency staff. Often, the students of these courses have little authority to implement the recommendations offered, and the policy makers who do have that authority are rarely involved.

More recently the FHWA has developed a Traffic Signal Timing Manual and is currently promoting the formation of Regional Traffic Signal Management Programs. Regional collaboration allows signal operators to leverage the expertise and resources within the region to clearly articulate operations objectives and performance measures that resonate at a region level often attracting support for and investment in the management and operation of signal systems.

Making progress in the context of these very difficult issues is a tremendous challenge, both technical and organizational. Organizational improvements must support technical improvements, and technical improvements are necessary to meet organizational objectives. Instilling those objectives and improvements will require achieving a clarity of understanding concerning where traffic signal management should be hopeful and where expectations should be moderated.

The industry often promises what it cannot deliver, and then fails to deliver what it could, with better commitment and resources.

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