Master of Science in Civil Engineering (MSCE)


Civil and Environmental Engineering

Document Type



Inefficient operation of traffic at work zone areas typically leads to increase in travel time delays, queue length, fuel consumption, number of forced merges, and roadway accidents. In order to improve the operational efficiency of work zones, research on freeway work zones constantly seeks to develop different lane merge control strategies, in addition to the conventional lane merge configuration, recommended by the Manual on Uniform Traffic Control Devices. This study evaluates the operational efficiency and safety benefits of a newly proposed configuration, joint lane merge (JLM), and compare its performance with the conventional lane merge (CLM) configuration. A simulation model (VISSIM) was calibrated with real-world data from an existing work zone on I-55 and used to simulate a work zone area with both configurations. A total of 25 different scenarios were generated from five different levels of demand and five truck percentages. Performance measures in terms of total throughput, average delay time, uncomfortable decelerations, speed variance and speed differential were compared for both configurations. Statistical analysis was conducted to determine the differences in operational and safety performance between both configurations. The results showed that the joint lane merge outperformed the conventional lane merge by a maximum of 12.6% improvement in throughput and 94.83% reduction in average delay time at high levels of demand. The results also indicate that the conventional lane merge configurations are more suitable for sites with relatively high percentage of trucks, while joint lane merge configurations are more suitable for sites with low percentage of trucks. The safety performance measures indicate that joint lane merge is safer as compared to conventional lane merge for volumes lower than or equal to 1500 vph.



Document Availability at the Time of Submission

Release the entire work immediately for access worldwide.

Committee Chair

Ishak, Sherif