Freeway congestion leads to mobility delays, wasted fuel, reduced safety and air quality impacts. Weather conditions also cause delays and increase the potential for crashes.  Active Traffic Management (ATM) systems such as Variable Speed Limit (VSL) and Variable Advisory Speeds (VAS) provide traffic and weather responsive guidance to drivers and have shown promise for reducing congestion and weather-related crashes by reducing drivers’ speeds.

The Oregon Department of Transportation is currently implementing ATM, VSL, and VAS systems on state highways. Evaluating the performance of initial systems will be vital for determining how and where to implement similar systems around the state. This project will evaluate the performance of two systems:

• The OR 217 installation project is on a congested 7 mile segment of urban highway in the Portland area. The project includes a weather-responsive VAS, posting of real-time travel times, queue warning, infrared and laser weather detection sensors, and a weather-responsive curve warning system.
• The US26/OR 35 Mount Hood Safety and Traveler Information Project covers 67 miles of rural highway. It includes VSL, VAS, a variable message sign (VMS), and a Road Weather Information System.

This project will collect before and after data to evaluate the system’s impact on speed, crash occurrence, traveler experience, driver behavior and other factors. The findings will be used to produce lessons learned and implementation guidance for future project deployments.