Pedestrian and Bicyclist Traffic Control Device Evaluation Methods
EXECUTIVE SUMMARY
Walking and cycling are modes of transportation that can help improve air quality and quality of life. Unfortunately, they are also hazardous because pedestrians and bicyclists are vulnerable when their movements interact with vehicular traffic. Traffic control devices are a low-cost safety solution that inform, warn, and regulate all road users. Effective traffic control devices can promote walking and cycling by providing a feeling of security to users. As new traffic control device technologies and applications are introduced, cost-benefit evaluations are necessary, and these evaluations are often conducted by local and State agencies.
This report is intended to educate practicing engineers, planners, and public works employees at the local, county, and State levels in conducting or overseeing an evaluation of traffic control device effectiveness. The guidance provided, though presented in the context of devices meant for pedestrian and bicyclist facilities, can be applied in a more general sense to evaluations of traffic control devices in any setting.
The Federal Highway Administration (FHWA), through its Manual on Uniform Traffic Control Devices (MUTCD), requires evaluations of the effectiveness of new traffic control devices.(1) When determining whether these countermeasures are effective, most engineers and planners rely on anecdotal observations or their professional judgment. In some cases, a limited quantitative safety evaluation is conducted. However, these evaluations are typically limited in scope, experimental design, and statistical rigor because many State and local agencies lack research funds or the specialized knowledge of experimental design and statistics necessary to conduct reliable evaluations of new traffic control devices or other traffic features.
This report is organized as follows:
- Chapter 1 presents a brief overview of the evaluation process and discusses the use of surrogate measures of safety.
- Chapter 2 provides details on the process used by FHWA to make changes to MUTCD. It discusses the distinction between interpretation and experimentation as well as the process to request experimentation.
- Chapter 3 presents six steps to plan an evaluation of a new traffic control device.
- Chapter 4 presents information on how to conduct an evaluation as well as information on sample size and statistical analysis. It focuses primarily on measures of effectiveness (MOEs), such as speed and volume counts, which should be familiar to most traffic engineers.
- Chapter 5 describes how to properly document the evaluation effort in a research report.
- Chapter 6 lists additional resources for practitioners to use to conduct, analyze, and report on evaluations.
- Appendix A provides an example of the process for an actual pedestrian crossing treatment. The steps are as follows:
- Planning step 1: Problem identification—What is the safety or traffic operations issue?
- Planning step 2: Evaluation question—What is the research question?
- Planning step 3: Measures of effectiveness—How will performance be assessed?
- Planning step 4: Evaluation designs—What is the study approach?
- Planning step 5: Evaluation methods—How are users, traffic, or crashes measured?
- Planning step 6: Components of the evaluation plan—How can time, budget, and practicality be balanced to execute the plan?
- Appendix B presents more detailed information on statistical analysis.
- Appendix C presents additional MOEs that focus on human behavior.
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