Accident Rate Module (Item# A-03)

It enables you to compute accident rates for intersection accidents and non-intersection accidents. It includes the following features:

You may assign any weights to injury and fatal accidents (for example, you may assign 1 injury accident = 3 property damage only accidents, 1 fatal accident = 10 property damage only accidents)

You may compute the accident rates on any accident locations you have selected. The way it works is as follows. You may select locations by clicking on the map. Once the locations are selected, AIMS will provide a list of all the selected locations on the screen, plus a blank entry next to each location. The blank entry is for user to enter traffic volume for each location. After the user has entered the traffic volumes, users simply clicks a button, the accident rate for each location will be computed. Instead of selecting locations from the map, you may select location by query. For example, you may want to query or sort all accidents that happened on Friday in 1999. AIMS will retrieve all accidents according to your query. Once the accidents have been sorted out, AIMS will provide a list of all the sorted accident locations on the screen, plus a blank entry next to each location. User simply enters the traffic volume, and AIMS will compute the accident rates automatically.

Both intersection and non-intersection accident rates are computed as mention in the previous paragraph. For non-intersection accidents, however, there will be an extra entry next to each location. This extra entry is for user to enter the length of each non-intersection or mid-block section.

If Traffic Volume Module (A-04) is included in AIMS, AIMS will automatically look for traffic volumes from the volume database for each accident locations. If it finds the volume, it will list the traffic volume out next to the corresponding accident location. User can use this volume for computing accident rate, or override it with his/her volume.

Besides computing accident rates based on traffic volume and/or section length, it will compute accident index based on the assigned weights to injury and fatal accidents. That is, accident index = number of property damage only accidents + number of injury accidents * injury accident weight + number of fatal accidents * fatal accident weight   

Intersection accident rate and non-intersection accident rate are computed according to the formulae in Traffic Engineering Handbook published by the Institute of Transportation Engineer.

It produces the following statistics and reports:

·        Number of accidents per location per year

·        Number of property damage only accidents per location per year

·        Number of injury accidents per location per year

·        Number of fatal accidents per location per year

·        Accident Index per location per year (based on injury and fatal weights)

·        Traffic volume per location per year

·        Section length per location per year

·        Accident rates per location per year (based on volume and length)

·        Accident rates per location for all years

·        Location ranking by accident rate (locations arranged according to accident rate, locations with highest accident rates are listed first)

·        Location ranking by accident index (locations arranged according to accident index, location with the highest accident indices are listed first)