This final report describes a research study that implemented and evaluated a program named Heed the Speed designed to reduce vehicle speeds in residential neighborhoods. The study was sponsored by the National Highway Traffic Safety Administration (NHTSA).
There is abundant evidence that higher speeds are associated with more severe pedestrian injuries and death (Leaf and Preusser, 1999). One study has reported that 5 percent of pedestrians will die if a vehicle traveling at 20 miles per hour strikes them (Department of Transport, 1997). The study further reported that 45 percent will die if the striking vehicle is traveling at 30 miles per hour, 85 percent will die if the vehicle is traveling at 40 miles per hour, and almost all will die if the vehicle is traveling at 50 miles per hour. In addition, a NHTSA national survey revealed that drivers feel that speeding is more dangerous on residential streets than on other roadways, and that drivers believe that higher posted speeds will result in increased danger to neighborhood residents ( Boyle, Dienstfrey and Sothoron, 1998) .
There has been significant work on engineering approaches to traffic calming as a means to reduce neighborhood speeds (c.f., Ewing , 1999, Stuster, Coffman, and Warren, 1998) . There has also been research on the effects of enforcement and education on speeding behavior that suggests that the effects they achieve may be more transitory than those produced by the physical changes associated with traffic calming. NHTSA noted, however, that there have been few attempts to combine public information and enforcement techniques with engineering changes as a means of achieving greater speed reductions. NHTSA therefore funded the current study whose objective was to:
Develop and test a behavior-based program to reduce motorist speed in residential areas by adding education and enforcement to engineering.
Preliminary project discussions with professionals from areas with active traffic calming programs revealed that some communities have used traffic calming on selected streets in a neighborhood but left others untouched because of objections voiced by emergency services and others. This procedure has created streets within a defined calmed neighborhood where motorists can (and probably do) exceed prudent speeds – or at least exceed the speeds on adjacent streets. Other communities have used traffic calming on a street-by-street basis. This process typically has resulted in traffic calming on side streets, but collector/arterial streets have remained unchanged, again largely because of emergency services concerns. It therefore seemed reasonable to utilize enforcement and education to attempt to achieve on these untreated streets a level of calming consistent with that on the adjacent streets that have received physical calming treatments.
As a result of these discussions, it was determined that the study should focus on identifying the following types of streets/neighborhoods for this study:
- Neighborhoods/streets that have not been traffic calmed and where no traffic calming is planned . This focused on the effects of education and enforcement alone on non-calmed streets.
- Neighborhoods/streets in which traffic calming has been in place for some time. This studied the effects of adding education and enforcement to existing traffic calming measures.
- Neighborhood streets that have not been traffic calmed but implementation of traffic calming measures is planned during the study period. This provided information on the effects of the concurrent implementation of education, enforcement, and engineering.
To achieve the objective of the study, the following tasks were conducted:
- Literature search . The identification and review of speed-related studies that have been completed since NHTSA produced its literature review on vehicle travel speeds (Leaf and Preusser, 1999).
- Expert workshop . A meeting of a panel of experts to explore the problem of speeding in neighborhoods, to identify promising countermeasures and to identify appropriate measures for use in assessing program success.
- Selection of test sites. Development of site selection criteria, personal contact with eligible cities to determine their interest in supporting the program, and final site selection. The availability and interest of two contiguous cities – one large and one small – resulted in the selection of two Arizona cities ( Phoenix and Peoria ) as test sites.
- Development of the countermeasure implementation and evaluation program . Development of education countermeasures to be implemented in the test sites plus plans for implementing the education, enforcement, and engineering countermeasures. For this task, the police departments of both test cities agreed to complete a form on all drivers stopped for speeding in the neighborhoods during the study. In addition, the engineering departments of both cities sponsored surveys to assess community awareness of program activities and accomplishments and provided traffic volume and speed measurements.
- Evaluation of program results . Analysis of the police forms completed on drivers stopped for speeding, the survey returns, the speed data collected on all study streets, and the process data.
- Preparation of a community guide . Preparation of a guide to assist other communities in implementing speed reduction programs.
The subsequent sections of this final report describe the study approach and present the results and conclusions derived from the study:
- Section II provides background information regarding the literature reviewed and persons contacted and the expert workshop.
- Section III describes the site selection process for the two Arizona cities of Phoenix and Peoria .
- Section IV describes the countermeasure program implemented in the two cities.
- Section V describes program evaluation procedures and results.
- Section VI provides a discussion of the results obtained from the study.
- Appendix A is a letter report of the results of the literature review conducted as part of the development of the study design.
- Appendix B contains a letter report documenting the activities and results of an expert panel session to generate ideas and provide guidance to the study design and evaluation.
- Appendix C contains black and white copies of program education countermeasures and supporting materials that were used in Peoria and Phoenix .
- Appendix D contains program data collection forms.
- Appendix E contains diagrams of the Phoenix and Peoria streets/neighborhoods that were studied.
- Appendix F contains a draft guide for communities to use when developing Heed the Speed programs.