In North Carolina, wrong way driving (WWD) crashes are one of the most severe traffic crashes that often result in a fatality or serious injury since they involve head-on or opposite direction sideswipe crashes at high speeds. To minimize the occurrence of WWD crashes, the North Carolina Turnpike Authority (NCTA), which is a unit of the North Carolina Department of Transportation (NCDOT), deployed a wrong way vehicle detection system along the Monroe Expressway in 2018. The system can automatically detect wrong way vehicles at mainline stations and inform traffic management center operators.
This project evaluated the effectiveness of wrong-way traffic control devices installed at the ramp and mainline locations along the Monroe Expressway. A comprehensive literature search was conducted to summarize the state-of-the-practice of WWD crash modeling, detection, and prevention. Real-world traffic data including traffic volume, traffic control devices present, geometry and configuration of interchanges were employed for identifying the relationship between the frequencies of wrong way incidents and facility characteristics. During the study period of approximately 1.5 years of data collection, there were 13 actual WWD events, of which five wrong way movements originated from the roundabout parclo interchanges on the Monroe Expressway. In addition, this project collected statewide data on partial cloverleaf interchanges to assess the risk for wrong way movements. It was found that the partial cloverleaf interchange configuration was associated with the highest number of WWD activities, and factors that affect the risk of WWD mainly include: entrance and exit ramp traffic volume and control type, divided or undivided exit ramp, median cut turn access, left-turn perpendicular turning distance, skew angle, and distance between ramp terminals.