Assessment of Dynamic Speed Limit Management on Metropolitan Freeways

Soriguera, Francesc; Torné, J. M.; Rosas, Dulce

doi:10.1080/15472450.2012.719455

Cited by 36 publications

(33 citation statements)

References 11 publications

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“…The results of the study showed slightly increased throughput and a positive impact on emission reduction, but increased TTS. In another study, Soriguera et al (2013) demonstrated the effectiveness of VSL in reducing accident risk, emissions and fuel consumption, but at the expense of higher induced delays. Lee et al (2013) developed a Cooperative Vehicle Intersection Control (CVIC) for urban intersection by optimizing vehicle trajectories to avoid crashes and examined positive impacts on mobility and environment.…”

Section: Literature Reviewmentioning

confidence: 98%

Variable speed limit: A microscopic analysis in a connected vehicle environment

Khondaker

Kattan

2015

Transportation Research Part C: Emerging Technologies

238

103

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a b s t r a c tThis paper presents a Variable Speed Limit (VSL) control algorithm for simultaneously maximizing the mobility, safety and environmental benefit in a Connected Vehicle environment. Development of Connected Vehicle (CV)/Autonomous Vehicle (AV) technology has the potential to provide essential data at the microscopic level to provide a better understanding of real-time driver behavior. This paper investigated a VSL control algorithm using a microscopic approach by focusing on individual driver's behavior (e.g., acceleration and deceleration) through the use of Model Predictive Control (MPC) approach. A multi-objective optimization function was formulated with the aim of finding a balanced trade-off among mobility, safety and sustainability. A microscopic traffic flow prediction model was used to calculate Total Travel Time (TTT); a surrogate safety measure Time To Collision (TTC) was used to measure instantaneous safety; and, a microscopic fuel consumption model (VT-Micro) was used to measure the environmental impact. Real-time driver's compliance to the posted speed limit was used to adjust the optimal speed limit values. A sensitivity analysis was conducted to compare the performance of the developed approach for different weights in the objective function and for two different percentages of CV. The results showed that with 100% penetration rate, the developed VSL approach outperformed the uncontrolled scenario consistently, resulting in up to 20% of total travel time reductions, 6-11% of safety improvements and 5-16% reduction in fuel consumptions. Our findings revealed that the scenario which optimized for safety alone, resulted in more optimum improvements as compared to the multi-criteria optimization. Thus, one can argue that in case of 100% penetration rates of CVs, optimizing for safety alone is enough to achieve simultaneous and optimum improvements in all measures. However, mixed results were obtained in case of lower % penetration rate which showed higher collision risk when optimizing for only mobility or fuel consumption. This indicates that with such % penetration rate, multi-criteria optimization is crucial to realize optimum and balanced benefits for the examined measures.

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Section: Literature Reviewmentioning

confidence: 98%

Variable speed limit: A microscopic analysis in a connected vehicle environment

Khondaker

Kattan

2015

Transportation Research Part C: Emerging Technologies

238

103

View full text Add to dashboard Cite

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“…A third study, in Germany, reported a slight decrease in capacity after VSL implementation (Weikl et al, 2013). A fourth study, in Spain (Soriguera et al, 2013), indicated the VSL system did not have any impacts on the capacity. This article reports the results of the performance of a VSL system in the United States.…”

Section: Review Of Vsl Literaturementioning

confidence: 98%

“…In terms of capacity improvements, a slight decrease in capacity of freeway was observed. Soriguera, Torné, and Rosas (2013) used empirical data and traffic simulation models to evaluate a VSL system on a 14.5-km segment of the C32 freeway in Spain. The primary objective of the system was to reduce air pollution in the nearby metropolitan area.…”

Section: Review Of Vsl Literaturementioning

confidence: 99%

Operational Analysis of a Freeway Variable Speed Limit System in St. Louis, Missouri

Kianfar

Edara

Sun

2015

Journal of Intelligent Transportation Systems

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Variable speed limit (VSL) systems have been more widely implemented inEurope compared to the United States. Studies have demonstrated positive safety impacts of such systems; however, there are very few studies that used actual deployment data to investigate the operational benefits of VSL systems. This article presents the operational impacts of a VSL deployment on Interstate 270 in the state of Missouri in the United States.Techniques such as parametric curve fitting, nonparametric methods, and other statistical tests were used to identify the changes between before and after traffic conditions. The effect of VSL on traffic performance was investigated at eight heavily congested locations. The two-dimensional Kolmogorov-Smirnov test results indicated that flow-occupancy diagram changes were statistically significant at seven out of eight locations. The slopes of flow-occupancy plots for over critical occupancies were found to be steeper after VSL. Slight changes in critical occupancy were observed after VSL implementation. However, the changes were inconsistent across locations, with some witnessing an increase and others witnessing a decrease. The maximum flow prior to breakdown (the prebreakdown flow) decreased at four locations and increased at four locations after VSL. The maximum flow after breakdown (the postbreakdown flow) decreased at three locations and increased at five locations after VSL. The average daily duration of congestion decreased at five locations and increased at three locations after VSL. Findings of this study help to develop VSL control algorithms that are more efficient in improving VSL traffic operations benefits.

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“…Ramp metering improves the merging efficiency by smoothing and restricting excessive ramp demand (Kotsialos, Papageorgiou, & Middelham, 2005;Jacobson, Stribiak, Nelson, & Sallman, 2006). Variable speed limits warn travelers of downstream congestion to allow smoother approaching congested segments (Borrough, 1997;Papageorgiou, Kosmatopoulos, & Papamichail, 2008;Hassan, Abdel-Aty, Choi, & Algadhi, 2012;Soriguera, Torné, & Rosas 2012;Carlson, Papamichail, & Papageorgiou, 2012;Kattan, Khondaker, Derushkina, & Poosarla, 2015;Lin, Kang, & Chang, 2015;Kianfar, Edara, & Sun 2015). However, to effectively improve the merging efficiency at those sections, the key control variable is in fact the density or vehicle gaps.…”

Section: Introductionmentioning

confidence: 99%

Gap metering for active traffic control at freeway merging sections

Jin

Fang

Jiang

et al. 2016

Journal of Intelligent Transportation Systems

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Freeway merging sections are critical segments that can recurrently activate peak-hour traffic congestion. This article proposes a novel vehicular gap control method as a new Active Traffic Management (ATM) strategy to be added to the existing Intelligent Transportation System (ITS) toolboxes for freeway merge control. The proposed strategy, "Gap Metering, " can be considered a non-stopping mainline version of ramp metering. It utilizes signals advising mainline through vehicles to yield sufficient gaps for merging vehicles. Detailed system design and control methods are proposed and implemented in VISSIM (please spell out the abbreviation of VISSIM for this first instance), a microsimulation software package. Different driver behavior sets with different standstill headway values are created to allow switching between gap-metered vehicles and regular vehicles. We evaluate the proposed system through two VISSIM models built and calibrated, respectively, for both the I-894 corridor in Milwaukee, WI, and the Riverside Drive segment on I-35 northbound in Austin, TX. Both corridors experience severe morning peak-hour congestion. We use the I-894 corridor for testing the system design parameters and use the I-35 corridor to conduct a comparison with the ramp metering strategies. The I-894 results indicate an average of 10-20% network delay reduction among all scenarios. We then tested the scenario on the I-35 corridor and compared with the ALINEAR ramp metering. Gap metering strategies alone or combined with ramp metering can, respectively, reduce 17% and 27% more total delay than ramp metering only control at 20% compliance rate.

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Assessment of Dynamic Speed Limit Management on Metropolitan Freeways

Cited by 36 publications

References 11 publications

Variable speed limit: A microscopic analysis in a connected vehicle environment

Variable speed limit: A microscopic analysis in a connected vehicle environment

Operational Analysis of a Freeway Variable Speed Limit System in St. Louis, Missouri

Gap metering for active traffic control at freeway merging sections

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