Intelligent Transportation Systems


Intelligent Transportation Systems Laboratory


Welcome to the ITS Lab web site at Portland State University. We've released our Annual Report for 2011-12. Read the report here.


Intelligent Transportation Systems Laboratory's Featured Project:

Determining Optimum Safety Countermeasures for Speed Related Crashes: Comparison of Identification and Ranking Methodologies for Speed Related Crash Locations

Over 60,000 crashes were reported on the Oregon state highway system from 2000-2002. Of these, speed was a primary causal factor in 27% of total crashes and 36% of all fatal crashes. Excessive speed is a driver behavior that can be influenced by a wide variety of countermeasures. However, different methods for analyzing crash data often results in setting different priorities for safety improvements. The state of Oregon currently does not have a developed methodology for prioritizing locations for review of countermeasure deployment. When making decisions about countermeasure deployment with limited resources, it is important they be allocated to locations that will result in the greatest impact. The objective of this research is to improve the procedures used to select locations for speed related safety countermeasures. The report includes a literature review focused on the relationship between speed and crashes as well as past research on speed reduction techniques. An analysis of speed-related crash data indicates that a number of variables such as ice, curves, and others are overrepresented in speed crashes. Based on these findings, the report then develops and compares alternate ranking methods for speed-ice high crash locations, including a unique refinement of the rate quality control (RQC) method using climate data that helps identify road segments that exhibit statisti

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