research >>planning level safety forecasting
PLANSAFE Beta Testing and User Interface Refinement
This project involves the pilot testing and further refinement of PLANSAFE, a forecasting tool that will significantly help state departments of transportation and metropolitan planning organizations to include safety in their transportation planning processes, as required by federal law.
It strengthens their forecasting abilities of the safety impacts of their decisions in the following ways: it allows them to incorporate socio-demographic-induced changes as well as infrastructure changes, so that they can generate reliable estimates for the safety impacts of engineering countermeasures and behavioral countermeasures under a multitude of growth scenarios; and it gives planners the ability to make forecasts at scales larger than corridor and project levels, which is the scope of most existing tools.
Under current methods, state departments of transportation and metropolitan transportation planners are forced to rely on current crash frequencies or rates projected into the future. This approach hampers their planning capabilities because these rates can not take into account important dynamic factors:
- socio-demographic-induced changes such as traffic volume growth, population growth, the addition of new schools and other trip-generating facilities, the aging of the population, etc., which will lead to changes in the expected safety of the system; and
- the impact of future safety countermeasure investments such as new policies, laws, behavioral programs, or technologies.
The initial phase of this project, NCHRP 8-44, resulted in the development of an analytical core in the form of a forecasting tool. However, it does not address a sufficient variety of conditions, and it is not user-friendly at present.
SafeTREC and its partners will roll out and test a user-friendly software interface, intended to allow transportation planners to employ it in sketch planning/scenario analysis. In addition, the project will calibrate analytical core components to local conditions so it will be suitable across jurisdictions.
The final product will enable planners to make estimates of current and future safety, and evaluate the impacts of safety countermeasure investments. It also will improve the preparation of input data (i.e. socio-economic, demographic, and road network characteristics data in zonal level) for transportation planners before forecasting traffic safety.