An Integrated Variable Speed Limit with Dynamic Hard Shoulder Running for Urban Freeway Traffic Control
Date
2018-01-12
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Abstract
Many urban road transportation systems currently face serious problems regarding safety, along with issues of capacity shortage and unreliability. These factors not only have a local and direct effect on the transportation system in any city, but cause the inefficient use of fuels and as a result environmental pollution. To successfully manage congestion and safety issues using only the existing infrastructure, there is a need for efficient and dynamic traffic management strategies. This thesis introduces a novel dynamic control strategy, which includes the dynamic use of a proactive Variable Speed Limit (VSL) integrated with the dynamic use of Hard Shoulder Running (HSR) and in which both VSL and HSR would be proactively triggered. The “dynamic” nature of this strategy would allow for the optimum utilization of the existing roadway network. Whereas, the “proactive” nature of the trigger would allow for necessary control measures to be taken in advance to avoid the formation of a bottleneck. For traffic prediction, a modified METANET model has been developed which takes into consideration the complex nature of driver’s behavior along with driver’s compliance, capacity drop and posted speed limits. The modified METANET model is more efficient than conventional macroscopic prediction models in detecting the traffic congestions. This dynamic and proactive strategy was tested on Deerfoot Trail using exclusively developed integrated VISSIM-COM-MATLAB interface. A detailed comparison between No VSL, VSL only and VSL-HSR control strategy has been made. Both VSL only and VSL-HSR control strategy were effective in improving the overall network performance. Importantly, VSL-HSR control strategy outperformed the VSL only strategy. The results from this study suggested that with VSL-HSR control strategy, there was a significant increase in both the average speed, by 21.09%, and in vehicle-throughput, by 33.44%. Furthermore, there was a noticeable reduction in the average travel time by 39.98% and in the total number of stops, by 32.43%. Importantly, the safety analysis performed using Surrogate Safety Assessment Model (SSAM) revealed a marked reduction in collisions, by 29.73%.
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Variable Speed Limit, Hard Shoulder Running, Temporary Use of Peak Period Shoulder Lane, Microsimulation, Macroscopic, Optimization, Driver Behavior, Deerfoot Trail, VISSIM COM, SSAM, METANET, Integrated Control Strategy, Traffic Management
Citation
Arora, K. (2018). An Integrated Variable Speed Limit with Dynamic Hard Shoulder Running for Urban Freeway Traffic Control (Master's thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca.