Operational Evaluation of Dynamic Lane Merging In Work Zones with Variable Speed Limits

AbstractIntelligent Transportation System (ITS) technology has been developed to improve the safety and mobility of traffic in and around work zones. In several states in the US, use of Dynamic Lane Merge (DLM) system has been initiated to enhance traffic safety and smooth traffic operations in work zone areas. The DLM usually takes two forms; dynamic early merge and dynamic late merge. The use of variable speed limit (VSL) systems at work zones is also one of those measures. It is anticipated that the VSL systems improve safety by helping the driver in determining maximum speed that he or she should travel. Besides adding improvement to safety, they are also expected to improve mobility at the work zones.The main goal of this paper is to report on an evaluation of operational effectiveness of the DLMS systems i.e. the Dynamic Early Lane Merge and Dynamic Late Lane Merge, in presence of a VSL system. More specifically, the VISSIM model was utilized to simulate a 2-to-1 work zone configurations for six scenarios namely: Work Zone without VSL and without DLMS, Work Zone with VSL and without DLMS, Work Zone with VSL and Early DLMS, and Work Zone with VSL and Late DLMS, Zone with Early DLMS and without VSL and Zone without VSL and with Late DLMS. Assessment of the effectiveness of these scenarios in terms of throughput to various traffic demands and motorists’ adherence level were conducted.It was found through the simulation of above mentioned scenarios that for low and medium demand volume levels (V0500, V1000 and V1500), that there is no significant difference between the Maintenance of Traffic (MOT) plans for mean throughputs. However, for higher demand volume levels (V2000 and V2500), late SDLMS with and without VSL produced higher mean throughputs for all compliance rates and truck percentages except when the demand volume was 2,500 vph and compliance of 60%, where it produces the significantly lower mean throughputs. © 2011 Published by Elsevier Ltd