Variable speed control: state-of-the-art and synthesis

Smulders, S A; Helleman, D.E.

doi:10.1049/cp:19980174

Cited by 17 publications

(6 citation statements)

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“…Concerning the environmental impacts, the system implemented on the M25 in the UK has resulted in reductions of exhaust emissions by 2-8%, depending on type of emission (Highway Agency, 2007). In addition, a state-of-the-art study on systems implemented in Germany, the Netherlands and the UK shows results for Germany and the Netherlands that are in line with the findings in the UK, with harmonized flows as the most highlighted benefit (Smulders and Helleman, 1998). No significant improvements could be concluded on congestion, throughput and capacity in this study.…”

Section: Variable Speed Limit Systems (Vslss)supporting

confidence: 85%

Analysis of a cooperative variable speed limit system using microscopic traffic simulation

Grumert

Tapani

2015

Transportation Research Part C: Emerging Technologies

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Section: Variable Speed Limit Systems (Vslss)supporting

confidence: 85%

Analysis of a cooperative variable speed limit system using microscopic traffic simulation

Grumert

Tapani

2015

Transportation Research Part C: Emerging Technologies

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“…The main objectives of these approaches were harmonization of speed differences and stabilization of traffic flow. Examples of such systems were developed by Zackor (1979), Smulders (1990), Smulders and Helleman (1998), Rama (1999), and Piao and McDonald (2008). These studies were successful in showing the effectiveness of VSL systems in harmonizing traffic and mainly improving safety.…”

Section: Literature Reviewmentioning

confidence: 99%

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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“…The effect of dynamic speed limits on traffic behavior strongly depends on whether the speed limits are enforced or not, and on whether the speed limits are advisory or mandatory, which also determines the suitability for a certain application. Most application oriented studies [111,122,128] enforce speed limits, except for [70]. Enforcement is usually accepted by the drivers if the speed limit system leads to a more stable traffic flow.…”

Section: Field Tests and Simulation Studiesmentioning

confidence: 99%