When a Department of Transportation (DOT) or agency performs a highway safety study, the study typically focuses on an existing corridor with a documented safety issue. Such studies often are reactive, looking for the root causes of crashes and testing a series of solutions in an existing corridor. The results are safety plans that lead to the recommendation of innovative or proven solutions, which help to reduce or eliminate factors that contribute to the crashes in a corridor.
Safety studies require a great amount of data, from existing crash information and daily traffic volumes to roadway characteristics such as number and width of lanes to type of shoulder and even the horizontal and vertical curvature of the roadway. Inaccurate or poor data is a detriment to a study’s fidelity.
Many state agencies utilize internally developed databases that commonly include data on interstates and other major routes. However, they often have limited data when it comes to minor streets and roadways because those facilities are typically maintained at the city or county level. In fact, according to the U.S. Government Accountability Office (GAO), locally maintained roads account for about 77% of all public roads in the nation, while state-maintained roads represent just 20% of total road mileage.
Incomplete data can make it challenging to identify hazardous locations and it can be a roadblock to identifying and reporting on potential solutions for hazardous locations. As a result, agencies can have difficulty applying a data-driven, strategic approach to highway safety. Without data to factually back up their plans, agencies may have difficulty securing funding and addressing their top traffic safety priorities.