Decisions concerning safety could be broad or very specific. In any case it requires knowledge of the safety impacts of a decision so that they can be considered together with other factors. Sometimes the safety impacts can be based on crash-only data bases such as FARS and GES in the United States. However, knowledge of highway design factors could be essential. A data base must include linkable files of crash, highway design, road network data and traffic flow data. In the US the Highway Safety Information System (HSIS) is designed to provide this capability. HSIS uses data collected by eight states and therefore it can provide both a large sample and the opportunity for multi-state verification of findings. This paper will provide an overview of HSIS and will attempt to highlight issues that might be useful in planning multi-jurisdictional data bases. It covers topics such as data collection and data quality maintenance, GIS and data analysis methods. Some example uses of the data for safety issues is also presented.
Abstract