Description:
The Safety Priority Index System (SPIS) is a network screening tool that can be used to evaluate public roadways (State and local) for segments with high crash histories. It is a three-year sliding window approach to network screening. The list of sites is not used to prioritize projects, but to provide a list of sites to be studied in further detail. The SPIS score is the sum of three indicators: crash frequency; crash rate; and crash severity.
1. Crash frequency accounts for 25 percent of the SPIS score and is maximized when there are 150 or more total crashes in a three year period.
2. Crash rate accounts for 25 percent of the SPIS score and is maximized when there are seven or more crashes per million entering vehicles.
3. Crash severity accounts for 50 percent of the SPIS score and is maximized when a combined severity rating greater than or equal to 300 is reached in a three year period. Fatal and severe injury (A) are given a rating of 100, moderate (B) and minor (C) injuries are given a rating of 10, and property damage only (PDO) crashes are given a rating of 1.
Note that the method only considers crash data along the mainline, and does not consider side street crashes at intersections. SPIS formulas and thresholds can be changed using the Oregon Adjustable Safety Index System (OASIS).
Tool Type:
Software
Owner Source:
state
Sponsor/Owner:
- Oregon Department of Transportation (ODOT)
Published:
Availability:
The tool is available free of charge at the following link: Oregon Safety Priority Index System.
Disclaimer:
This information is disseminated under the sponsorship of the U.S. Department of Transportation in the interest of information exchange. The U.S. Government assumes no liability for the use of the information contained herein. This information does not constitute a standard, specification, or regulation. The U.S. Government does not endorse products or manufacturers. Trademarks or manufacturer's names appear in this information only because they are considered essential to the objective of this publication.
Any opinions, findings, and conclusions or recommendations, and translations thereof, expressed in this publication are those of the author(s) and do not necessarily reflect the views of the Federal Highway Administration.