scholarly journals Optimal subwork zone operational strategy for short-term work zone projects in four-lane two-way freeways

2010 ◽  
Vol 47 (2) ◽  
pp. 151-169 ◽  
Author(s):  
Qiang Meng ◽  
Jinxian Weng
Author(s):  
Andrew G. Beacher ◽  
Michael D. Fontaine ◽  
Nicholas J. Garber

The traffic control strategy of the late merge in work zones was devised to improve flow and safety at work zone lane closures. Although some states have put the strategy into practice, only a handful of short-term field studies have formally evaluated its effectiveness. Additional field studies were necessary to assess the efficacy of the strategy and its proper deployment. This paper documents the results of a field test of the late merge traffic control conducted over several months. The late merge strategy was evaluated by comparing its effectiveness with that of traditional plans for work zone lane closures. The field test was conducted on a primary route in Tappahannock, Virginia, at a two-to-one lane closure. Results showed that throughput increased, but the increase was not statistically significant. Likewise, time in queue decreased, but the decrease was not statistically significant. These results were much less dramatic than those of other studies. Possible reasons for this disparity include different driver populations, road types, vehicle mixes, and site-specific characteristics. Despite limited improvements in throughput and time in queue, more drivers were in the closed lane, a positive response to the late merge signs.


2012 ◽  
Vol 2012 ◽  
pp. 1-18 ◽  
Author(s):  
Rami Harb ◽  
Essam Radwan ◽  
Vinayak V. Dixit

Traffic safety and mobility of roadway work zones have been considered to be one of the major concerns in highway traffic safety and operations in Florida. Dynamic lane merging (DLM) systems—ITS-based lane management technology—were introduced by several states in an attempt to enhance both safety and mobility of roadway work zones. Two forms of lane merging, namely, the early merge and the late merge were designed to advise drivers on definite merging locations. Up to date, there are no studies that contrast both merging schemes under matching work zone settings. This study simulates a two-to-one work zone lane closure configuration under three different Maintenance of Traffic (MOT) plans in VISSIM. The first MOT is the conventional plans used in Florida’s work zones, the second MOT is a simplified dynamic early merging system (early SDLMS), and the third MOT is a simplified dynamic late merging systems (late SDLMSs). Field data was collected to calibrate and validate the simulation models. Simulation results indicated that overall, under different levels of drivers’ compliance rate and different percentages of trucks in the traffic composition, the early SLDMS outperformed the conventional MOT and the late SDLMS in terms of travel times and throughputs.


Author(s):  
Wayne A. Sarasua ◽  
William J. Davis ◽  
David B. Clarke ◽  
Jayaram Kottapally ◽  
Pawan Mulukutla

Author(s):  
Gerald L. Ullman ◽  
Paul J. Carlson ◽  
Nada D. Trout

Results of research conducted to investigate the short-term effects of the double-fine law in work zones implemented in Texas on January 1, 1998, are presented. Field studies of traffic speeds in several work zones were performed before and after the law was implemented. Traffic citation data for these same work zones were also obtained from the Texas Department of Public Safety. Analyses showed that traffic speeds in the work zones 4 to 6 months after the law was enacted were essentially unchanged from before the law was enacted. Similarly, citation frequency and fines levied were not significantly higher than they were before enactment of the law. The data suggested that a higher proportion of drivers who were issued citations after the law was implemented chose to take defensive driving training and to have the ticket subsequently dismissed. However, researchers could not determine whether this was due to the increased fine or to other external reasons.


Author(s):  
Gerald L. Ullman

Research conducted to explore the effects of natural diversion on traffic conditions and travel patterns upstream of temporary work zone lane closures on high-volume urban freeways in Texas is described. Specific objectives were to explore how natural diversion affects traffic volumes at the exit and entrance ramps upstream of the lane closures and the interrelationships between the freeway and frontage road operating conditions that develop at a closure and the amount of natural diversion that occurs. The field studies showed that the rate of queue growth upstream of the short-term lane closures diminished significantly after the first hour at each site. Eventually, the queues approached a balanced state in which the upstream end of the queue became almost stationary. This stabilization was due to significant reductions in entrance ramp volumes both upstream of the freeway queue and within the limits of queuing, as well as to changes in exit ramp volumes within the queue. As a result of these ramp volume changes the constrained flow rate within the queue increased as a function of the distance upstream of the actual lane closure. Using the theory of shock waves in a traffic stream it was shown that the changes in ramp volumes and resulting impact on constrained freeway flow rates within the queue were consistent with the queue stabilization process observed at each site.


2018 ◽  
Vol 144 (9) ◽  
pp. 04018050
Author(s):  
Ossama E. Ramadan ◽  
Virginia P. Sisiopiku
Keyword(s):  

Author(s):  
Gerald L. Ullman ◽  
Conrad L. Dudek

A new theoretical approach is described that more accurately predicts the length of queues that will develop when one or more lanes are closed for short-term freeway road work in an urban area. A model was developed that represents the interactions between diversion and traffic queuing on the freeway. The model is based on macroscopic fluid-flow analogies of traffic and a new perspective of the freeway corridor as a section of permeable pipe. Historical traffic volumes on the roadway serve as the primary data input into the model. Unlike other work zone analysis methods, the model presents a rational representation of how traffic queues stabilize upstream of temporary work zone bottlenecks in urban areas. The model can be calibrated to reasonably represent the magnitude of traffic queues developing upstream of actual work zone lane closures on urban freeways in Texas.


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