Traffic Safety Investigations for Local Agencies

National and statewide (California) collision numbers are currently on the decline; however, the U.S. is declining at a much slower rate than most other developed countries, and in some aspects is actually regressing in terms of traffic safety. Although state highway safety is improving, local roadway safety may actually be regressing. Approximately three-quarters of all U.S. public roadways, and approximately 80% of all injury accidents fall under the jurisdiction of cities. However, cities may not be allocating the proper level of resources, or operating under the proper administrative methodologies to adequately address these safety issues. This research finds that on average, California cities are experiencing increasing annual collision rates. In particular, small cities with populations of less than 25,000 are experiencing the largest increases, whereas larger cities are experiencing static or slightly decreasing collision rates. California’s statewide collision statistics and the administration surveys conducted as part of this study indicate that there is a correlation between a city’s administrative analysis/mitigation methodologies and their annual collision rate trends. Specifically, cities with lower traffic engineering staff to population ratios tend to have increasing collision rates, as opposed to cities with high staff to population ratios, which have decreasing collision rates. Also, this research shows that cities that allocate more traffic safety resources to enforcement over engineering tend to have increasing collision rates, as opposed to cities allocating more resources to engineering that have decreasing collision rates. This research also finds that there are predominant and correctable factors that lead to the various collision types. Cities that employ routine system wide traffic safety audits addressing location-specific collision trends based on these predominant factors tend to have decreasing collision rates, as opposed to those that do not. In general, collision rates among U.S. cities are increasing largely due to increasing rates on roadways within the jurisdiction of smaller cities, most commonly with populations under 25,000. Over one-third of cities are not staffed at the proper levels, not allocating the necessary resources to traffic engineering activities, and are not employing an adequate evaluation/mitigation strategy. The findings of this study provide guidance and framework to cities for developing effective traffic safety strategies by identifying the characteristics of those cities that have been successful in reducing collision rates as examples. In particular the value of this research is important for non-engineering administrative staff and political bodies in terms of establishing appropriate staffing levels and resource allocations necessary for an effective traffic safety program. The findings of this study provide guidance and framework to cities for developing effective traffic safety policy preference by identifying the characteristics of those cities that have been successful in reducing collision rates as examples. In particular this research is important for non-engineering administrative staff and political bodies in terms of establishing appropriate staffing levels and resource allocations necessary for a transportation department to be effective in reducing traffic collisions and resulting damages.

Name thesis:degree_name

MS in Civil and Environmental Engineering

Discipline thesis:degree_discipline

Civil and Environmental Engineering

Year dc:date.available

2010

Author dc:creator

• Hudson, Jacob D

Contributors dc:contributor

• Anurag Pande

• Traffic
• Transportation
• Safety
• Collisions
• Civil and Environmental Engineering

Identifier

10.15368/theses.2010.162

OAI identifier oai:identifier

oai:digitalcommons.calpoly.edu:theses-1434