New traffic control methods for mobile work zones and their effectiveness in reducing crashes

In Oregon, an approach that has improved experience with mobile work zones on freeways has been the deployment of advance roadside PCMS with specific messages similar to “road work 5 mph/ left lane, next 5 miles” plus a truck with PCMS on the shoulder within 1/2 mile of the work with a “left lane closed ahead” message. Most people move over well ahead of time and stay over in the open lane. It’s not fool proof, so to speak, nor is the equipment or roadside space always available.
Oregon’s alternative on high-risk roadways (volumes/speeds) is to close a lane for a distance roughly equal to a shift’s work. This is costly in terms of crew time and traffic control devices for maintenance crews, impacting the amount of work that can be accomplished for the dollars. However, this type of traffic control has shown no crashes, day or night, and ODOT is working out the parameters for making it standard when the risk outweighs the costs.