Knowledge Resources

The Federal Highway Administration (FHWA) partnered with the American Association of State Highway and Transportation Officials (AASHTO) to encourage the implementation of work zone ITS through an AASHTO Technology Implementation Group (TIG) project. This effort led to a workshop in September 2005, in St. Louis, MO. Sue Groth, Assistant State Traffic Engineer, gave a presentation on implementation of a dynamic late merge system (DLMS) and other work zone ITS applications.

Minnesota Department of Transportation's (Mn/DOT’s) Construction Office and Traffic Office developed a specification for a DLMS and worked closely with the vendor capable of providing the system. Mn/DOT reviewed other state DOT's (e.g., Michigan, Kansas, and Maryland) experience with dynamic merge technologies to determine the proper strategy for Mn/DOT work zones. The system Mn/DOT deployed provided guidance to motorists on proper lane usage via portable changeable message signs (PCMS). When congestion level was reached, the PCMS were activated. When traffic returned to free-flow the PCMS returned to “dark mode.” The costs provided were based on four DLMS study locations: three in urban settings and one in a rural location. The cost of detection was approximately $300 per day and three PCMS cost $600 per day for a total cost of $900 per day per direction.

For the 2005 construction season, Mn/DOT will include DLMS as a pay item in construction projects and require vendors to be on a Qualified Product List (QPL).