scholarly journals Dynamic traffic management on a familiar road: Failing to detect changes in variable speed limits

2016 ◽  
Vol 38 ◽  
pp. 37-46 ◽  
Author(s):  
Ilse M. Harms ◽  
Karel A. Brookhuis
Keyword(s):  
Traffic Management ◽  
Variable Speed ◽  
Dynamic Traffic ◽  
Speed Limits ◽  
Variable Speed Limits

Evaluation of Operational Effects of I-66 Active Traffic Management System

2017 ◽  
Vol 2616 (1) ◽  
pp. 91-103 ◽  
Author(s):  
PilJin Chun ◽  
Michael D. Fontaine
Keyword(s):  
Travel Time ◽  
Traffic Management ◽  
Management System ◽  
Travel Time Reliability ◽  
Variable Speed ◽  
Time Data ◽  
Speed Limits ◽  
Variable Speed Limits ◽  
Traffic Management System ◽  
Virginia Department

In September 2015, the Virginia Department of Transportation instituted an active traffic management system on I-66 in Northern Virginia. I-66 is a major commuter route into Washington, D.C., that experiences significant recurring and nonrecurring congestion. The active traffic management system sought to manage existing capacity dynamically and more effectively with hard shoulder running, advisory variable speed limits, lane use control signs, and queue warning systems. An initial before-and-after analysis of the system’s operational effectiveness was performed with probe-based travel time data from the provider, INRIX, and used records from the active traffic management’s traffic operations center. On weekdays, statistically significant improvements were often observed during off-peak periods, but conditions did not improve during peak periods. Weekends showed the greatest improvements, with travel times and travel time reliability measures improving by 10% to 14%. Segment-level analysis revealed that most of the benefits were attained because of the use of hard shoulder running outside of the peak periods, which created additional capacity on I-66. Benefits due to advisory variable speed limits were inconclusive because of limited data.

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.

An integrated control method based on the priority of ways in a freeway network

2016 ◽  
Vol 40 (3) ◽  
pp. 843-852 ◽  
Author(s):  
Minghui Ma ◽  
Shidong Liang
Keyword(s):  
Traffic Congestion ◽  
Control Method ◽  
Integrated Control ◽  
Adaptive Controller ◽  
Ramp Metering ◽  
Traffic Density ◽  
Variable Speed ◽  
Speed Limits ◽  
Variable Speed Limits ◽  
Freeway Networks

Traffic congestion is a common problem in merging regions of freeway networks. An adaptive integrated control method involving variable speed limits and ramp metering is presented with the aim of easing traffic congestion at merging regions. The problem of the imbalanced rights of ways of the upstream mainline and on-ramp at the merging region is solved by constructing the evaluation indices of congestion degree. Specifically, the traffic density and queue length of the upstream mainline and on-ramp are selected for use in the evaluation indices. Then, an adaptive controller is designed, integrating variable speed limits and ramp metering. The proposed method is tested in simulations considering a real freeway network in China calibrated by real traffic variables. The results show that the proposed adaptive integrated control method can prevent traffic flow breakdown and maintain a high outflow at the merging region during peak periods. The adaptive integrated control may lead to a 17% improvement in traffic delay.

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