Simulation Study Found a 28 Percent Reduction in Weighted Average Travel Time at 100 Percent Connected and Automated Vehicle Market Penetration Rate in Sydney.
Simulation Analysis of Connected and Automated Vehicles Found Improvement in Both Travel Time and Travel Time Reliability in Urban Transportation Network.
Sydney
Impact of connected and automated vehicles on the travel time reliability of an urban network
Summary Information
Connected and automated vehicles (CAVs) could potentially benefit the transportation industry with both reduced travel times and road congestion while also improving safety. This study demonstrated how various market penetration rates (MPRs) of CAVs in an urban network affected network travel time reliability using traffic simulation. The simulation focused on a four-square kilometer (1.54 square-mile) area in eastern Sydney, New South Wales, Australia. The study utilized traffic volumes and signal data from November 4 through 15, 2019, to calibrate the model for the morning peak hour.
METHODOLOGY
The simulation network had 37 intersections, 32 of which were signalized, four roundabouts, and one priority intersection. The simulation analyses were conducted for CAV MPRs between zero and 100 percent, with 10 percent increments, on 11 origin-destination (OD) matrices in the network (121 simulated scenarios in total). The study then evaluated network performance using various travel time reliability indicators, such as weighted average travel time, standard deviation, buffer time index, and misery index.
FINDINGS
- When the MPR of CAV increased from zero to 100 percent, the overall weighted average travel time decreased by 28 percent.
- The standard deviation of the weighted average travel time decreased by 35 percent when the MPR increased from zero to 100 percent, indicating an increase in travel time reliability.
- When the MPR increased from 30 to 40 percent, the weighted average travel time decreased by seven percent, which was the highest reduction amongst each 10 percent increment. In contrast, the weighted average travel time showed the smallest reduction of one percent when the MPR increased from 60 to 70 percent.
- The buffer time index (considers the extra time needed for travel in case of delays) showed a decrease of at least 60 percent for almost half of the simulated OD pairs when the MPR increased from zero to 100 percent, signifying an improvement in travel time reliability.
- The misery index (considers the average of the worst travel times and the extent of the delay experienced) showed a decrease of at least 10 percent for 70 percent of the simulated OD pairs when the MPR of CAVs increased from zero to 100 percent, further highlighting an increased travel time reliability with higher MPRs
