How can you evaluate traffic signal timing plan performance?

1 Method 1: Field observations

One of the simplest and most direct ways to evaluate traffic signal timing plan performance is to observe the traffic conditions in the field. You can use a stopwatch, a camera, or a smartphone app to record data such as vehicle delays, queues, stops, speeds, and travel times. You can also note any issues such as congestion, spillback, blocking, or violations. Field observations can help you identify the strengths and weaknesses of your traffic signal timing plan, and provide you with valuable feedback from the users' perspective.

2 Method 2: Signal performance measures

Another way to evaluate traffic signal timing plan performance is to use signal performance measures (SPMs). SPMs are numerical indicators that quantify the quality and efficiency of traffic signal operations. They can be derived from data collected by detectors, controllers, or other devices at the signalized intersections. Some examples of SPMs are split failures, cycle failures, progression quality, arrival type, and system-wide travel time. SPMs can help you monitor and compare the performance of different traffic signal timing plans, and identify potential areas for improvement.

3 Method 3: Simulation models

A third way to evaluate traffic signal timing plan performance is to use simulation models. Simulation models are computer programs that mimic the behavior and interactions of traffic elements, such as vehicles, pedestrians, cyclists, and signals. They can help you test and analyze the impacts of different traffic signal timing plans on various scenarios and conditions, such as peak hours, off-peak hours, incidents, or special events. Simulation models can help you visualize and evaluate the performance of traffic signal timing plans in a controlled and realistic environment.

4 Method 4: Surveys and interviews

A fourth way to evaluate traffic signal timing plan performance is to use surveys and interviews. Surveys and interviews are methods of collecting qualitative data from the stakeholders and users of the traffic signal system, such as drivers, pedestrians, cyclists, transit operators, emergency responders, or business owners. They can help you understand the perceptions, preferences, expectations, and satisfaction of the people who are affected by the traffic signal timing plan. Surveys and interviews can help you gain insights and feedback that may not be captured by other methods.

5 Method 5: Performance indices

A fifth way to evaluate traffic signal timing plan performance is to use performance indices. Performance indices are composite measures that combine multiple SPMs or other indicators into a single value that represents the overall performance of the traffic signal system. They can help you simplify and communicate the results of your evaluation, and compare the performance of different traffic signal timing plans or locations. Some examples of performance indices are level of service, mobility index, reliability index, and safety index. Performance indices can help you summarize and present the performance of traffic signal timing plans in a concise and meaningful way.

6 Method 6: Cost-benefit analysis

A sixth way to evaluate traffic signal timing plan performance is to use cost-benefit analysis. Cost-benefit analysis is a method of comparing the costs and benefits of different traffic signal timing plans or alternatives. The costs can include the capital, operation, and maintenance costs of the traffic signal system, as well as the external costs of traffic delays, emissions, noise, and accidents. The benefits can include the travel time savings, fuel savings, emission reductions, noise reductions, and accident reductions of the traffic signal system. Cost-benefit analysis can help you determine the economic feasibility and efficiency of traffic signal timing plans.

7 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?