Use of Portable and Dynamic Variable Speed Limits in Construction Zones

2018 ◽  
Vol 2672 (16) ◽  
pp. 35-45
Author(s):  
Josh Van Jura ◽  
David Haines ◽  
Andrew Gemperline
Keyword(s):  
Intelligent System ◽  
Speed Limit ◽  
Department Of Transportation ◽  
Variable Speed ◽  
Construction Work ◽  
Work Zones ◽  
Dynamic Variable ◽  
Variable Speed Limit ◽  
Speed Limits ◽  
Variable Speed Limits

The Utah Department of Transportation (UDOT) implemented dynamic management of portable variable speed limit (PVSL) technology to reduce regulatory speed limits through an active work space (AWS). UDOT also developed and tested an intelligent system approach to alter speed limits in construction work zones. The goal of the PVSL system was to provide a portable and dynamic system that was easy for construction personnel to use to prudently reduce speeds within an AWS and make construction work zones safer for workers and the traveling public, while limiting the need to reduce speed throughout the AWS, rather than the entire construction work zone. This was achieved through temporary regulatory reductions in driver speeds within the immediate boundary of an AWS when workers were on site and exposed to the danger of errant vehicles during active construction. The system also raises speed limits when workers were not present. This PVSL system used a dynamic variable speed limit (VSL) algorithm to raise and lower the regulatory speed limits. The PVSL system also provided a queue warning algorithm that operated independent of the VSL algorithm to control messages posted on the portable variable message sign (PVMS) trailers to disseminate dynamic information to drivers. UDOT has completed 2 years of PVSL system deployment testing in four separate construction work zones to evaluate the effectiveness of the system. This paper highlights key elements that guided development of the PVSL system, along with the successful results from deployment of the system.

Numerical Simulation of Traffic Flow in the Tollgate Area with Variable Speed Limits

2011 ◽  
Vol 130-134 ◽  
pp. 3404-3409
Author(s):  
Wen Xing Zhu ◽  
Zhi Ping Jia
Keyword(s):  
Traffic Flow ◽  
Velocity Model ◽  
Flow Speed ◽  
Open Boundary ◽  
Speed Limit ◽  
Variable Speed ◽  
Variable Speed Limit ◽  
Speed Limits ◽  
Optimal Velocity ◽  
Variable Speed Limits

We investigate behaviors of vehicles passing a controlled area with variable speed limits (VSL) before a tollgate. The traffic flow mathematical model is formulated based on optimal velocity model. The typical sketch of tollgate area is plotted and variable speed limit signs are set in the area to control the traffic flow speed for fear of accident and congestion. Simulations are carried out to examine the influence on traffic flow passing the controlled area with different number of the speed limit signs under open boundary condition. The simulations results show that more speed limit signs may reduce the risk of rear-end collision and the occurrence of the congestion in the tollgate area.

scholarly journals Variable Speed Limit Signs: Control and Setting Locations in Freeway Work Zones

2017 ◽  
Vol 2017 ◽  
pp. 1-13 ◽  
Author(s):  
Wei Wang ◽  
Zeyang Cheng
Keyword(s):  
Model Comparison ◽  
Programming Model ◽  
Speed Limit ◽  
Variable Speed ◽  
Work Zones ◽  
Total Delay ◽  
Variable Speed Limit ◽  
Speed Limits ◽  
Freeway Work Zones ◽  
Bilevel Programming Model

Variable Speed Limit Sign (VSLS) Systems enable speed limits to be changed dynamically in response to traffic conditions so that traffic incidents can be reduced significantly on freeway work zones. In this paper, we examined how many and where VSLS are to be placed and the speed limits to be set and proposed a bilevel programming model to perform this decision making operation. The appropriate speed limits and deployments of VSLS were got by case study, and they were analyzed by a simulation to prove the empirical features of traffic breakdown at freeway work zones. Then the results of model comparison and simulation evaluation illustrate that the proposed method outperforms existing models in terms of maximizing information benefit and minimizing average queue length, total delay, and total stop frequency on the freeway work zone.

scholarly journals Homogenization Effects of Variable Speed Limits

2014 ◽  
Vol 15 (2) ◽  
pp. 130-143 ◽  
Author(s):  
Alvaro Garcia-Castro ◽  
Andres Monzon
Keyword(s):  
Weather Conditions ◽  
Variable Speed ◽  
Variable Speed Limit ◽  
Speed Limits ◽  
Key Indicator ◽  
Variable Speed Limits ◽  
Performance And Emissions ◽  
Speed Management ◽  
Road Performance

Abstract Changing factors (mainly traffic intensity and weather conditions) affecting road conditions require a suitable optimal speed at any time. To solve this problem, variable speed limit systems (VSL) - as opposed to fixed limits - have been developed in recent decades. This term has included a number of speed management systems, most notably dynamic speed limits (DSL). In order to avoid the indiscriminate use of both terms in the literature, this paper proposes a simple classification and offers a review of some experiences, how their effects are evaluated and their results This study also presents a key indicator which measures the speed homogeneity and a methodology to obtain the data based on floating cars and GPS technology applying it to a case study on a section of the M30 urban motorway in Madrid (Spain). It also presents the relation between this indicator and road performance and emissions values.

scholarly journals Evaluation of Variable Speed Limit Pilot Projects for Texas Department of Transportation

2016 ◽  
Vol 15 ◽  
pp. 676-693
Author(s):  
Beverly Kuhn ◽  
Kevin Balke ◽  
Robert Brydia ◽  
Luann Theiss ◽  
Ioannis Tsapakis ◽  
...  
Keyword(s):  
Speed Limit ◽  
Department Of Transportation ◽  
Variable Speed ◽  
Pilot Projects ◽  
Variable Speed Limit ◽  
Texas Department

Simulation and Analysis of the Variable Speed Limit Controls on Highway Maintenance

2011 ◽  
Vol 97-98 ◽  
pp. 435-439 ◽  
Author(s):  
Bai Ying Shi ◽  
Xue Yu Gao ◽  
Zhi Ge ◽  
Xue Ping Ma
Keyword(s):  
Traffic Safety ◽  
Traffic Control ◽  
Simulation Software ◽  
Speed Limit ◽  
Variable Speed ◽  
Work Zones ◽  
Microscopic Simulation ◽  
Variable Speed Limit ◽  
Control Zone ◽  
Organization And Management

Despite of the fact that the traffic control zone for maintenance work (work zone) has been recognized as one of major priorities to guarantee the traffic safety, only one conventional posted speed limit (PSL) strategy is applied into the organization and management. This article presents the strategy of the variable speed limit (VSL) on highway work zones that brings about gradual deceleration and low speed variance. To evaluate the safety of the proposed VSL strategy, this study uses the microscopic simulation software VISSM to estimate the traffic flow and adopt transversal and longitudinal coefficients of safety (MSDE and cv) to compare the different speed limit strategies. The results of simulation and analysis confirm that VSL yield a substantial decrease the traffic turbulence caused by speed limit and increase the traffic safety throughout work zones.

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