TREC research addresses complex transportation problems by drawing on multiple disciplines, including engineering, planning, economics and design, from across the Portland State University campus. Use the search box at right to search for a specific project.

Research Highlights

Unsupervised Approach to Investigate Urban Traffic Crashes Based on Crash Unit, Crash Severity, and Manner of Collision

Farzin Maniei Stephen Mattingly
Both crash frequency analysis (CFA) and real-time crash prediction models (RTCPMs) typically divide a highway into segments with a constant length for data aggregation. Despite the significant impact of the segment length in several previous traffic safety studies, no standard approach exists for determining a recommended segment length for crash data aggregation. This research investigates the impact of fragment size (segment length) on traffic crash data aggregation and establishes a… Read More

NCHRP 15-73 Design Options to Reduce Turning Motor Vehicle – Bicycle Conflicts at Controlled Intersections

Christopher Monsere Sirisha Kothuri , Nathan McNeil
BACKGROUND One of the most common locations for fatal motor vehicle-bicyclist crashes is at intersections, which inherently have a large number of turning conflicts. Reducing these conflicts is a key objective in improving intersection safety across all modes. Of particular concern for bicyclists’ safety at intersections are the conflicts between straight-through bicyclists and motor vehicle right-turns and opposing left-turns. Despite the widespread acknowledgement of this problem,… Read More