Could driverless cars cause more congestion in urban cores?

As the era of driverless cars looms, a new Boston-based study suggests the vehicles may increase traffic congestion in downtown areas as more people embrace ride-hailing services and abandon transit.

The same study also found, however, that driverless vehicles could dramatically improve traffic conditions in the suburbs.

The study by the World Economic Forum and the Boston Consulting Group is based on a simple premise, backed by 10 months of research and one of the most specific surveys done on autonomous cars: As the cost of using services such as Uber and Lyft comes down because the companies no longer need to pay drivers, people who take mass transit will opt for door-to-door service rather than the bus or subway.