01557823

Component

Systems that enable high levels of vehicle-automation are now beginning to enter the commercial marketplace. Road vehicles capable of operating independently of real-time human control under an increasing set of circumstances will likely become more widely available in the near future. Such vehicles are expected to bring a variety of benefits. Two such anticipated advantages (relative to human-driver vehicle control) are said to be increased road network capacity and the freeing up of the driver-occupant’s time to engage in their choice of leisurely or economically-productive (non-driving) tasks. In this study the authors investigate the implications for intersection capacity and level-of-service of providing occupants of automated (without real-time human control), autonomously-operating (without vehicle-to-X communication) cars with ride quality that is equivalent (in terms of maximum rates of longitudinal and lateral acceleration) to two types of rail systems: [urban] light rail transit and [inter-urban] high-speed rail. The literature suggests that car passengers start experiencing discomfort at lower rates of acceleration than car drivers; it is therefore plausible that occupants of an autonomously-operating vehicle may wish to instruct their vehicle to maneuver in a way that provides them greater ride comfort than if the vehicle-control algorithm simply mimicked human-driving-operation. On the basis of traffic microsimulation analysis, the authors found that restricting the dynamics of autonomous cars to the acceleration/deceleration characteristics of both rail systems leads to reductions in a signalized intersection’s vehicle-processing capacity and increases in delay. The impacts were found to be larger when constraining the autonomous cars’ dynamics to the more restrictive acceleration/deceleration profile of high-speed rail. This paper concludes with a brief discussion of research needs to advance this line of inquiry.

This paper was sponsored by TRB committee AHB30 Vehicle-Highway Automation. Alternate title: The Tension Between Autonomous Cars’ Impacts on Intersection Level of Service and Their Occupants’ Use of Travel Time for Leisure or Economically Productive Activities

01550057

15-3936

English

27p

2015

Transportation Research Board 94th Annual Meeting

Digital/other

Figures; Photos; References; Tables

Acceleration (Mechanics); Intelligent vehicles; Leisure time; Level of service; Motor vehicle dynamics; Passenger comfort; Ride quality; Signalized intersections

Highways; Operations and Traffic Management; Planning and Forecasting; Vehicles and Equipment; I91: Vehicle Design and Safety; I92: Vehicle Comfort

Transportation Research Board Annual Meeting 2015 Paper #15-3936

TRIS, TRB, ATRI

Dec 30 2014 1:17PM