Unravelling effects of cooperative adaptive cruise control deactivation on traffic flow characteristics at merging bottlenecks
Cooperative Adaptive Cruise Control (CACC) systems have the potential to increase roadway capacity and mitigate traffic congestion thanks to the short following distance enabled by inter-vehicle communication. However, due to limitations in acceleration and deceleration capabilities of CACC systems, deactivation and switch to ACC or human-driven mode will take place when conditions are outside the operational design domain. Given the lack of elaborate models on this interaction, existing CACC traffic flow models have not yet been able to reproduce realistic CACC vehicle behaviour and pay little attention to the influence of system deactivation on traffic flow at bottlenecks. This study aims to gain insights into the influence of CACC on highway operations at merging bottlenecks by using a realistic CACC model that captures driver-system interactions and string length limits. The authors conduct systematic traffic simulations for various CACC market penetration rates (MPR) to derive free-flow capacity and queue discharge rate of the merging section and compare these to the capacity of a homogeneous pipeline section. The results show that an increased CACC MPR can indeed increase the roadway capacity. However, the resulting capacity in the merging bottleneck is much lower than the pipeline capacity and capacity drop persists in bottleneck scenarios at all CACC MPR levels. It is also found that CACC increases flow heterogeneity due to the switch among different operation modes. A microscopic investigation of the CACC operational mode and trajectories reveals a close relation between CACC deactivation, traffic congestion and flow heterogeneity.
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Availability:
- Find a library where document is available. Order URL: http://worldcat.org/issn/0968090X
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Supplemental Notes:
- © 2018 Published by Elsevier Ltd. Abstract reprinted with permission of Elsevier.
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Authors:
- Xiao, Lin
- Wang, Meng
- Schakel, Wouter
- van Arem, Bart
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0000-0001-8316-7794
- Publication Date: 2018-11
Language
- English
Media Info
- Media Type: Web
- Features: References;
- Pagination: pp 380-397
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Serial:
- Transportation Research Part C: Emerging Technologies
- Volume: 96
- Issue Number: 0
- Publisher: Elsevier
- ISSN: 0968-090X
- Serial URL: http://www.sciencedirect.com/science/journal/0968090X
Subject/Index Terms
- TRT Terms: Autonomous intelligent cruise control; Bottlenecks; Highway capacity; Lane drops; Market penetration; Merging traffic; Microscopic traffic flow; Microsimulation; Traffic flow
- Subject Areas: Data and Information Technology; Highways; Operations and Traffic Management;
Filing Info
- Accession Number: 01684026
- Record Type: Publication
- Files: TRIS
- Created Date: Oct 24 2018 11:17AM