|This report is an archived publication and may contain dated technical, contact, and link information|
Publication Number: FHWA-HRT-11-035
Date: May 2011
Pedestrian and Bicyclist Traffic Control Device Evaluation Methods
CHAPTER 1. INTRODUCTION
State, county, and city transportation agencies implement a variety of innovative countermeasures to improve pedestrian and bicyclist safety (see figure 1). These countermeasures include the following:
Figure 1. Photo. Bar pair crosswalk intended to improve pedestrian and bicyclist safety.
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 often limited in terms of scope, experimental design, and/or statistical rigor because many State and local agencies lack research funds or sufficient knowledge of experimental design and statistics to conduct proper evaluations of new traffic control devices or other traffic features.
If better safety evaluation methods for pedestrian and bicyclist countermeasures were available to State and local agencies, local evaluations could provide sound safety effectiveness data for decision making on national standards like MUTCD or American Association of State Highway and Transportation Officials (AASHTO) guides and programs.
One problem with evaluating bicyclist and pedestrian safety treatments is the difficulty of using direct safety outcomes such as pedestrian and bicyclist crashes. These types of crashes are relatively infrequent and therefore occur in small quantities. Consequently, any pedestrian or bicyclist safety evaluation that uses a crash-based analysis would require tens or hundreds, if not thousands, of study sites to obtain statistical significance. This is often impractical or impossible in typical experiments involving innovative devices. Additionally, local agencies rarely have the resources necessary to install and evaluate innovative traffic control devices at more than a few locations. As a result, surrogate MOEs are often the only feasible approach to evaluate the effectiveness of a device. A significant focus of this report is to provide an approach for establishing when a particular surrogate measure is appropriate.
The purpose of this report is to assist practitioners in conducting sound evaluations on the effectiveness of pedestrian and bicyclist traffic control devices. The report is designed for practitioners (State transportation departments, county or city engineers, and other traffic officials). Additionally, personnel without specialized statistical analysis skills should be
The report includes (but is not limited to) the following information:
This report provides basic information on each of these elements so that a sound evaluation can be conducted. A reliable evaluation, regardless of whether the results are positive or negative, will allow other practitioners to learn from and build on the experience of the implementation of a new traffic control device, placement, or application. Sound evaluations can also lead to the dismissal or elimination of a traffic control device either because it does not provide positive driver or pedestrian results or because it does not offer an improvement over existing traffic control options. One such example is the use of fluorescent yellow-green crosswalk markings. Evaluation of these markings showed that they offered no advantage over standard white crosswalk markings. Therefore, they were not adopted for further use.
FHWA and the National Committee on Uniform Traffic Control Devices (NCUTCD) rely on evaluations to determine if a new device or treatment should be adopted in MUTCD or if it should be considered for further evaluation. Although an evaluation conducted by one agency may not be sufficient to determine if a device should be adopted, the results may be combined with other evaluations completed by other agencies. Inadequate, incomplete, or improper evaluations will lead to poor decision making by agencies and other practitioners.
Key components or documents include the following:
Figure 2. Photo. The 2009 MUTCD.
The FHWA MUTCD team administers MUTCD, including the experimentation process, and is available to assist with technical questions or comments about MUTCD. Contact information for the team is available at http://mutcd.fhwa.dot.gov/team.htm.
Topics: research, safety
Keywords: research, safety, Evaluation methods, Guidelines, MUTCD, Pedestrian treatment, Bicyclist treatment, Traffic control device
TRT Terms: research, safety