%0 Journal Article
%T Evaluating Variable Speed Limits and Dynamic Lane Merging Systems in Work Zones: A Simulation Study
%A Zaier Zaidi
%A Essam Radwan
%A Rami Harb
%J ISRN Civil Engineering
%D 2012
%R 10.5402/2012/435618
%X ITS technologies such as dynamic lane merging (DLM) and variable speed limits (VSL) have been deployed in roadway work zones in an attempt to enhance safety and mobility through vehicular traffic. The DLM system in its two main forms namely the early merge and the late merge was designed to advise drivers on definite merging locations whereas VSL were introduced to work zones to decrease speed fluctuations, variances, and to smoothen traffic through work zones. Up to date, there are no studies that contrast Maintenance Of Traffic (MOTs) plans including a combination of ITS technologies to standard work zones MOTs under matching work zone settings. This study simulates a two-to-one work zone lane closure configuration in VISSIM under six different MOT plans and compares work zone throughputs and travel times across MOTs namely Motorist Awareness System (MAS), early DLM, late DLM, VSL combined with MAS, a VSL and early DLM combination, and a VSL late DLM combination. Results showed that the combination of VSL and DLM or standalone DLM improve work zone throughputs and travel times compared to work zones with conventional static Florida MOT and work zones with VSL. 1. Introduction To improve traffic safety and mobility in work zone areas, several states of the USA explored the DLM and VSL systems. The DLM systems are intelligent work zone traffic control systems that respond to real-time traffic changes via traffic sensors. The DLM systems are designed to advise drivers on definite merging locations and can take two forms; dynamic early merge and dynamic late merge. The idea behind the dynamic early merge is to create a dynamic nonpassing zone, to encourage drivers to merge into the open lane before reaching the end of a queue and to prohibit them from using the closed lane to pass vehicles in the queue and merge into the open lane ahead of them [1]. The concept behind late merge is to make more efficient use of roadway storage space by allowing drivers to use all available traffic lanes to the merge point. Once the merge point is reached, the drivers in each lane take turns proceeding through the work zone [2]. Several studies were undertaken to contrast the early form of the DLM [1, 3¨C5] or the late form of the DLM [2, 6¨C11] to existing maintenance of traffic (MOT) plans or standard MUTCD work zone traffic control plans. Whereas each study exposes the advantages and disadvantages of the tested systems, up to date there are no studies that cross compare both merging schemes (i.e., early and late DLM) under the same work zone settings. VSL systems are a
%U http://www.hindawi.com/journals/isrn.civil.engineering/2012/435618/