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

The objective of this study is to evaluate the performance of a dynamic late merge (DLM) system for highway work-zone operations, tested by Maryland State Highway Administration. The evaluation is focused on both the operational efficiency such as the work-zone throughputs, and the resulting safety impacts on the upstream segment of the work zone. The evaluation results reveal that the deployed DLM system can indeed outperform the conventional merge control regarding an increase in the total work-zone throughputs, but such a system 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 the field observations and analysis results for the DLM performance improvement are also presented in this study.