Autonomous vehicles could increase congestion, warns WEF


The World Economic Forum (WEF) has released a study suggesting that while shared autonomous vehicles will reduce the number of cars and overall travel times in cities, they could also worsen traffic and increase travel times in downtown areas. 

The body’s findings came in a joint study with the Boston Consulting Group (BCG) and the City of Boston – Reshaping Urban Mobility with Autonomous Vehicles Lessons from the City of Boston.

"Cities can’t follow a ‘wait and see’ approach towards autonomous vehicles"

John Moavenzadeh, World Economic Forum

While autonomous vehicles will reduce the numbers of cars and travel times across cities as a whole, found the study, the effect is not evenly distributed, with concentrated downtown areas potentially seeing a deterioration in traffic flow.

The WEF called on city and state governments to put forward policies and incentives to maximise the benefits of autonomous vehicles and help to avoid pockets of congestion caused by passengers switching from mass transit.

“Cities can’t follow a ‘wait and see’ approach towards autonomous vehicles,” said John Moavenzadeh, member of the Executive Committee of the World Economic Forum 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.”

"Autonomous mobility on demand provides a very convenient door-to-door service with a guaranteed seat and convenient mobile booking"

Nikolaus Lang, BCG

As part of the study, the team carried out sophisticated traffic modelling for the City of Boston. The results showed that neighbourhoods outside the downtown core would see a reduction in traffic and decreased travel time, while travellers in downtown areas would face increased traffic and journey times. 

The study also indicated that a shift to autonomous mobility would lead to a 48% reduction in the number of parking spaces required in the city – creating significant opportunities for planners to rethink city streets and urban design.

The research team asked thousands of residents what types of autonomous and non-autonomous vehicles they would be likely to use in different circumstances. Their analysis predicts a clear shift to mobility-on-demand (both autonomous shuttles and non-autonomous vehicles like today’s taxi and ride-share services).

“Autonomous mobility on demand provides a very convenient door-to-door service with a guaranteed seat and convenient mobile booking – all this at very competitive prices,” said Nikolaus Lang, Senior Partner at BCG and co-author of the study. 

“For trips shorter than four miles, it is likely that travellers would opt for low-capacity autonomous taxis or shuttles rather than taking high-capacity mass transit options like buses or trains.”

As a result, found the research, the number of cars on the road in the city’s downtown neighbourhood would rise, with the average travel time there increasing by 5.5%.

The study highlighted a number of potential measures to improve citywide travel time, including: 

  • The introduction of occupancy-based pricing schemes to discourage sole ridership – potentially improving travel time by 15%

  • The conversion of on-street parking to dedicated pick-up or drop-off areas, surface mass transit or driving lanes – leading to a potential 10% decrease in travel time

  • The designation of dedicated lanes for shared autonomous vehicles – decreasing travel time by as much as 8%.

A full copy of the WEF report can be found here.