Existing Roadway Geometry Data
Many agencies maintain a system database, which includes existing system attributes such as number and width of lanes. While this data is generally readily available for interstates and other major routes, it is typically less complete for minor roadways.
Supplemental and Complementary Datasets
By assessing data deficiencies and adding missing, relevant datasets, agencies can build a more complete picture of the roadway’s safety challenges. Specifically, agencies can identify and integrate pre-crash, environment and post-crash third-party datasets into their existing systems to increase data quality to advance progress on highway-safety analysis.
Pre-crash datasets may be driver- or vehicle-oriented, such as citation histories or other crash predictors from Department of Motor Vehicles (DMV) datasets. Other pre-crash datasets are comprised of meteorological or naturalistic data, such as the findings from the Strategic Highway Research Program 2 (SHRP2).
Crowdsourced data sources, such as Waze, or other GPS navigation tools that provide user-submitted travel times and route details are also available. One helpful specific resource is data available through HERE Technologies. With aggregated data sourced from millions of datasets, HERE has developed databases that include roadway geometry, vehicle speeds and real-time traffic conditions, among other attributes.
Crash environment datasets are something all states are required to maintain in their statewide crash records. These systems provide a field that depicts the crash location, which can reveal more details about the built environment in which the crash occurred, such as roadway and land-use characteristics. These systems include official crash reports and associated details pertaining to individual crashes.
An additional third-party source to augment an agency’s existing data is Google Earth. This free resource requires users to manually extract data, such as lane width and shoulder width, and while some automation is possible, can provide a quick dataset easily obtained without performing a field visit.
Post-crash datasets can include hospitalization data, as well as medical insurance claims data, emergency medical system (EMS) data and vital statistics, many of which are managed by state Departments of Health.
Datasets of the Future
Vehicle event data recorder (EDR) technology can provide a detailed picture of the seconds right before and after a crash. These automotive “black boxes” record crash data and save moment-by-moment statistics, including speed, acceleration and braking. They may also record information from inside the car. The National Highway Traffic Safety Administration (NHTSA) has developed a final ruling that provides standards for the data collected by EDRs. While not currently mandated, many automotive manufacturers have implemented some form of EDR data collection.