摘要: |
Beginning in 1994, the HSIS system was converted to a relational database for internal use. the accident data are in three separate files. The Accident Subfile (including crashes from 1985-97), containing basic information on accident type, location, environment, etc. can be linked with the Vehicle Subfile (which contains information on each vehicle in the crash and each driver) and the Occupant Subfile (which contains information on each occupant in each vehicle and non-occupants such as pedestrians, pedalcyclists, etc.) through use of the accident case number, vehicle number, and year. The Roadlog File contains yearly characteristics of 14,000 miles of the road system including shoulder and median information, pavement type and width, lane information, etc. The Horizontal Curve and Vertical Grade Files were generated to produce information on specifics of curvature. This information contains degree of curve, direction of curve, and percent and direction of grade. |