While shared autonomous vehicles (AVs) will reduce the number of cars and overall travel times in cities, they will potentially worsen traffic and increase travel time in overcrowded areas.

The findings were revealed in a report by the World Economic Forum and The Boston Consulting Group (BCG) with the City of Boston in Massachusetts, US.

The joint study was carried out to predict the ground reality that the city may face once AVs become the mainstream mode of transportation.

The ‘Autonomous Vehicles: Lessons from the City of Boston’ report forecasts a clear shift toward mobility on demand that will account for 30% of all trips in the greater Boston area, up from the existing 7%. The report also predicts that AVs will account for 40% of trips within the city limits in the future.

“AVs are expected to cut the number of parking spaces in Boston by 48%, providing opportunities to rethink street and urban design.”

World Economic Forum executive committee member John Moavenzadeh said: “Cities can’t follow a ‘wait and see’ approach towards autonomous vehicles.

“Cities need to actively explore policies and incentives such as dynamic pricing, dedicated lanes, and redesign of the curb, 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.”

Outcomes of the study were used as the input assumptions for the traffic simulation model for the City of Boston, which showed that both the number of vehicles on the road and travel times would distinctly change.

The report highlights that while AVs in neighbourhoods outside downtown such as Allston would reduce traffic and travel time, they would worsen traffic and increase travel time downtown.

AVs are expected to cut the number of parking spaces in Boston by 48%, providing opportunities to rethink street and urban design.

In order to tackle the situation, the report recommends city and state governments to launch occupancy-based pricing schemes to discourage riding alone. This is expected to improve travel time by 15%.

The government is also required to convert on-street parking to dedicated pick-up or drop-off areas, surface mass transit, or driving lanes, which could lead to a 10% decrease in travel time.

It also recommends selection of dedicated lanes for shared AVs, which could reduce travel time by 8%.