Development and Evaluation of the Lane Merge Traffic Control System at Construction Work Zones

The majority of safety hazards and resulting traffic crashes that occur in lane closure areas in work zone are often due to the aggressive behavior of some drivers. The late lane merge phenomenon occurs when some drivers try to avoid slow moving traffic by traveling in the lane that is about to end, and then attempt to force merge in the through lane at the last moment. In an attempt to alleviate such aggressive driver behavior at work zones an innovative traffic control system was tested in Michigan. The Michigan Department of Transportation (MDOT) began a pilot project to study the effectiveness of a lane merge traffic control system (LMTCS), creating an enforceable no passing zone to encourage motorists to make an early merge. In Phase I of this study, test and control sites were examined in order to evaluate the effectiveness of the Michigan LMTCS, in terms of reducing delay, driver behavior and the effects of police enforcement. The research efforts for Phase II involved the development of an optimal traffic control system for work zone lane merges based on the experiences of the Phase I study and field testing of the same. During the Phase II, a comparison of the before and after data indicated that for similar flow rates, the average speeds increased. This may be due to the smoother traffic flow created by the dynamic LMTCS. Also, the average delay per vehicle to pass through the work zone and the number of aggressive driving maneuvers decreased due to the LMTCS.