Project Benefits

Dr. Joyce Emery - Iowa DOT, Office of Transportation Engineering and Safety

In highway safety engineering it is easy to stay busy addressing the problem locations that are brought to the attention of the State Safety Engineer. It may be due to a particularly tragic crash at that location, or to a perceived apprehension of one or more persons using that location that a hazard exists. While it is valid to review a location for safety when either of those circumstances exist, that modus operandi (spending all the effort "putting out fires") should not be the only or even the primary way that safety is approached by a state agency.

What is needed is a statewide crash surveillance system. Such a system would use statistical treatments of data to identify locations of potentially high hazard or that are characterized by a crash pattern that highway engineering can mitigate. Those locations would be printed out on a rank-ordered list for study by both state and local engineers.

Iowa has had such a system in place for many years, generating "Candidate Locations for Safety Improvements" lists using three equally weighted variables. It was a reasonable effort that was certainly within the state-of-practice of state transportation agencies. However, there are statistical techniques that can provide a more accurate ranking and much greater detail of how a location may be functioning outside of norms.

In order to bring the most effective statistical strategies into the state surveillance system in ways that state employees can operate and understand, researchers are needed to design and build the system. Making the statistical processing work effectively with the state crash data system and geographical information system are challenges that few state agencies are capable of addressing on their own, either because government staff do not have the skills or simply lack the time to do development work. The high-crash-location HRB project will go far toward putting this core need in place. This type of research project is a prime example of how researchers and government agency staff together can achieve very practical benefits for state highway users.

With a truly outstanding crash surveillance system, a state can make better use of resources in improving the locations most needing attention. Furthermore, it makes it much more likely that a poorly functioning location will be corrected prior to the occurrence of a headline-generating fatal crash. This has to be the overall goal--to detect and fix problems before deaths and serious injuries occur. The value of research which leads to such a system is enormous.