A joint World Economic Forum (WEF) and Boston Consulting Group (BCG) study, in collaboration with the City of Boston, finds that autonomous vehicles (AVs) could increase, not decrease, traffic in already overcrowded downtown areas, unless multiple occupancy is encouraged.
The study, Reshaping Urban Mobility with Autonomous Vehicles – Lessons from the City of Boston, notes that while AVs will reduce the numbers of cars and overall travel times across cities as a whole, the effect is not evenly distributed, with concentrated downtown areas potentially seeing a deterioration in traffic flow.
However, city and state governments can intervene to encourage higher sharing of AVs and avoid a significant move away from mass transit systems, which will remain essential for urban mobility. The study concluded that policymakers must expect the impact of AVs to vary, not only city by city, but also neighborhood by neighborhood, and incentives will be needed to maximize the technology’s benefits.
A sophisticated traffic simulation model for the City of Boston showed that both the number of vehicles on the road and travel times would change markedly. While neighborhoods outside the downtown core, such as Allston, would see a reduction in traffic and decreased travel time, travelers downtown would face increased traffic and travel time.
The study also indicated that a shift to autonomous mobility would reduce the number of parking spaces required by 48%, which unlocks new opportunities to rethink streets and overall urban design.
The team conducted a large-scale conjoint analysis, asking thousands of residents in the Boston area what types of autonomous and non-autonomous vehicles they were likely to drive in certain situations, such as when traveling to work when raining.
The analysis predicts a clear shift to mobility-on-demand (MOD) using both AVs or shuttles and non-autonomous taxi and rideshare services, which will account for 30% of all trips in the Greater Boston area (up from 7% today), and 40% of trips within the city limits in the future. The results of this consumer study were used as the input assumptions for the traffic simulation model.
The study’s suggestions to improve future citywide travel include:
• Introduction of occupancy-based pricing schemes to discourage riding alone, which could improve travel time by 15%;
• Conversion of what was once on-street parking to dedicated pick-up or drop-off areas, surface mass transit or driving lanes, which could lead to a decrease in travel time by 10%;
• Designation of dedicated lanes for shared autonomous vehicles, which could decrease travel time by 8%.
“Cities can’t follow a ‘wait and see’ approach toward autonomous vehicles,” said John Moavenzadeh, member WEF’s executive committee and co-author of the study. “Cities need to actively explore policies and incentives, such as dynamic pricing, dedicated lanes, and redesign of the kerb, to ensure that autonomous vehicles will achieve the full value for society that they promise. If such choices are not made, cities risk losing more than they will gain from autonomous vehicles.”