Evaluating the safety impact of connected and autonomous vehicles on motorways

Papadoulis, Alkis; Quddus, Mohammed; Imprialou, Marianna

doi:10.1016/j.aap.2018.12.019

Cited by 342 publications

(184 citation statements)

References 19 publications

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“…On the contrary, Rahman and Abdel-Aty [27] applied surrogate safety measures to evaluate the safety impact of exclusive lanes for CAVs. Besides, other research studies on the safety impacts of CAVs applied surrogate safety measures [28,29] presented the feasibility of this kind of evaluation. Details of aforementioned literatures are summarized in Table 1.…”

Section: Literature Reviewmentioning

confidence: 99%

Safety Evaluation for Connected and Autonomous Vehicles’ Exclusive Lanes considering Penetrate Ratios and Impact of Trucks Using Surrogate Safety Measures

Zhang

Cheng

et al. 2020

Journal of Advanced Transportation

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Plenty of studies on exclusive lanes for Connected and Autonomous Vehicle (CAV) have been conducted recently about traffic efficiency and safety. However, most of the previous research studies neglected comprehensive consideration of the safety impact on different market penetration rates (MPRs) of CAVs, traffic demands, and proportion of trucks in mixture CAVs with human’s driven vehicle environment. On this basis, this study is to (1) identify the safety impact on exclusive lanes for CAVs under different MPRs with different traffic demands and (2) investigate the safety impact of trucks for CAV exclusive lanes on mixture environment. Based on the Intelligent Driver Model (IDM), a CAV platooning control algorithm is proposed for modeling the driving behaviors of CAVs. A calibrated 7-kilometer freeway section microscopic simulation environment is built by VISSIM. Four surrogate safety measures, including both longitudinal and lateral safety risk indexes, are employed to evaluate the overall safety impacts of setting exclusive lanes. Main results indicate that (1) setting one exclusive lane is capable to improve overall safety environment in low demand, and two exclusive lanes are more suitable for high-demand scenario; (2) existence of trucks worsens overall longitudinal safety environment, and improper setting of exclusive lanes in high trucks, low MPR scenario has adverse effect on longitudinal safety; and (3) setting exclusive lanes have better longitudinal and lateral safety improvement in high-truck proportion scenarios. Setting one or two exclusive lanes led to [+42.4% to −52.90%] and [+45.7% to −55.2%] of longitudinal risks while [−1.8% to −87.1%] and [−2.1% to −85.3%] of lateral conflicts compared with the base scenario, respectively. Results of this study provide useful insight for the setting of exclusive lanes for CAVs in a mixture environment.

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Section: Literature Reviewmentioning

confidence: 99%

Safety Evaluation for Connected and Autonomous Vehicles’ Exclusive Lanes considering Penetrate Ratios and Impact of Trucks Using Surrogate Safety Measures

Zhang

Cheng

et al. 2020

Journal of Advanced Transportation

View full text Add to dashboard Cite

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“…The safety of the heterogeneous flow has been studied as well. Papadoulis et al (2019) assessed the safety benefit of CAV and found 12-47% reduction in traffic conflict at 25% MPR. Local coordination among CAV was implemented with a threshold of 0.6 s form the vehicle upstream and downstream in the target lane.…”

Section: Relevant Researchmentioning

confidence: 99%

Influence of CAV clustering strategies on mixed traffic flow characteristics: An analysis of vehicle trajectory data

Zhong

Lee

Nejad

et al. 2020

Transportation Research Part C: Emerging Technologies

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Being one of the most promising applications enabled by connected and automated vehicles (CAV) technology, Cooperative Adaptive Cruise Control (CACC) is expected to be deployed in the near term on public roads. Thus far, the majority of the CACC studies have been focusing on the overall network performance with limited insights on the potential impacts of CAVs on human-driven vehicles (HVs). This paper aims to quantify such impacts by studying the high-resolution vehicle trajectory data that are obtained from microscopic simulation. Two platoon clustering strategies for CACC-an ad hoc coordination strategy and a local coordination strategy-are implemented. Results show that the local coordination outperforms the ad hoc coordination across all tested market penetration rates (MPRs) in terms of network throughput and productivity. According to the two-sample Kolmogorov-Smirnov test, however, the distributions of the hard braking events (as a potential safety impact) for HVs change significantly under local coordination strategy. For both of the clustering strategy, CAVs increase the average lane change frequency for HVs. The break-even point for average lane change frequency between the two strategies is observed at 30% MPR, which decreases from 5.42 to 5.38 per vehicle. The average lane change frequency following a monotonically increasing pattern in response to MPR, and it reaches the highest 5.48 per vehicle at 40% MPR. Lastly, the interaction state of the car-following model for HVs is analyzed. It is revealed that the composition of the interaction state could be influenced by CAVs as well. One of the apparent trends is that the time spent on approaching state declines with the increasing presence of CAVs.

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“…Besides, the increase of road capacity indicates a smaller average headway, which may bring safety issues. To deal with this, studies were carried out to find a balance between increases of traffic capacity and accident risks [20,21].…”

Section: Literature Reviewmentioning

confidence: 99%

Influence of Lane Policies on Freeway Traffic Mixed with Manual and Connected and Autonomous Vehicles

Hua

Wang

et al. 2020

Journal of Advanced Transportation

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Connected and autonomous vehicles (CAVs) have become the highlights of traffic. Researchers in this field have proposed various traffic management measures to enhance the capacity and efficiency of traffic with CAVs, especially mixed traffic of CAVs and manual vehicles (MVs). Exclusive lane setting is included. However, exclusive lane policy-related researches for mixed traffic of CAVs and MVs were very limited, and the influence of number and location of exclusive lanes on the mixed traffic was unclear. To fill this gap, this paper aims to study the influence of different exclusive lane policies on mixed traffic and provide recommended lane policies under various traffic volumes and CAV penetration rates. Freeways with two lanes and three lanes in a single direction were taken into consideration, and sixteen lane policies were proposed. Then different lane policies were simulated with a new proposed cellular automata (CA) model, and properties including flux, average speed, and CAVs degradation were analyzed to evaluate the traffic efficiency of each lane policy. The results show that CAV exclusive lanes can improve the capacity, while MV exclusive lanes seem helpless for capacity improvement. Seven lane policies, including GC, GM, and CM for two-lane freeways and GCG, CGC, and CCM for three-lane freeways, outperform the others in terms of average speed. In addition, exclusive lanes can reduce the probability that CAVs degenerate to AVs. Our findings may help to optimize freeways’ lane policies and improve the efficiency of heterogeneous traffic mixed with CAVs and MVs.

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Evaluating the safety impact of connected and autonomous vehicles on motorways

Cited by 342 publications

References 19 publications

Safety Evaluation for Connected and Autonomous Vehicles’ Exclusive Lanes considering Penetrate Ratios and Impact of Trucks Using Surrogate Safety Measures

Safety Evaluation for Connected and Autonomous Vehicles’ Exclusive Lanes considering Penetrate Ratios and Impact of Trucks Using Surrogate Safety Measures

Influence of CAV clustering strategies on mixed traffic flow characteristics: An analysis of vehicle trajectory data

Influence of Lane Policies on Freeway Traffic Mixed with Manual and Connected and Autonomous Vehicles

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