Dynamic Late Merge Control at Highway Work Zones: Evaluation, Observations, and Suggestions

The purpose of this study is to present the evaluation result of a dynamic late merge (DLM) system for highway work zone operations, experimented by the Maryland State Highway Administration and International Road Dynamics Inc. The evaluation focuses mainly on the operational efficiency such as the input-output analysis, work zone throughput, volume distribution, and resulting queue length. Evaluation results reveal that a properly deployed DLM system can indeed outperform the conventional merge control with respect to the total work zone throughputs. Such a system, however, may result in excessive traffic conflicts if not properly integrated with existing static warning signs for work zone operations. Some suggestions and guidelines developed from field observations and analysis results for potential improvement of the DLM performance are also presented in this paper.