Driverless cars ‘will have every incentive to create havoc,’ warns transportation planner

Self-driving cars may cause endless traffic jams to avoid parking fees, per study

Traffic jam in downtown Los Angeles, CA, May 7, 2001. CREDIT: David McNew/Newsmakers via Getty Images.
Traffic jam in downtown Los Angeles, CA, May 7, 2001. CREDIT: David McNew/Newsmakers via Getty Images.

A new study warns that self-driving cars “could more than double” vehicle traffic in cities as they cruise around town rather than having to pay hefty parking fees.

Even worse, since cruising around is cheaper at slower speeds, driverless cars will have an incentive to go as slow as possible, according to a new report — “The Autonomous Vehicle Parking Problem” — in the journal Transport Policy by transportation planner Adam Millard-Ball.

For instance, 2,000 driverless cars in downtown San Francisco could slow traffic to less than 2 miles per hour according to the study’s traffic micro-simulation model.

“Autonomous vehicles have no need to park at all,” warned Millard-Ball. “They can get around paying for parking by cruising. They will have every incentive to create havoc.”


This raises a few questions. What is to stop a company like Uber from programming future driverless cars to work together to slow traffic down and thereby optimize their revenue rather than minimize overall congestion? Also, what will the impact on air pollution be from this increased congestion?

“The article’s conclusions should motivate public policy makers to require systems using Artificial Intelligence to provide information about how these systems operate,” Cordell Schachter, the chief technology officer for the New York City Department of Transportation, told ThinkProgress.

If companies selling driverless cars are allowed to keep their programming secret, then we will have no way of knowing whether those cars are designed to make congestion worse or not.

In reality, truly driverless cars — autonomous vehicles (AVs) with nobody behind the wheel — are probably more than a decade away according to many experts ThinkProgress has spoken to, including Schachter.


But it is a very real concern that when AVs are ready for primetime, they will just keep driving around rather than parking, thereby increasing congestion.

“Even when you factor in electricity, depreciation, wear and tear, and maintenance, cruising costs about 50 cents an hour — that’s cheaper than parking even in a small town,” said Millard-Ball.

That’s especially true for super-efficient all-electric AVs, where the urban cruising cost in the coming years is likely to be well below 50 cents an hour as the cost and performance of batteries and solar power get better and better.

One policy solution, as Schachter notes, is congestion pricing, which is basically a user fee. In London, for instance, drivers pay a daily charge of £11.50 (nearly $15). These charges help limit the number of overall cars, incentivize alternative commuting options, such as trains and subways, and thus reduce overall traffic.

But, as the study notes, congestion pricing is not politically popular with commuters and so it has been difficult to implement.


“The public never wants to pay for something they’ve historically gotten for free,” explained Millard-Ball. “But no one owns an autonomous vehicle now, so there’s no constituency organized to oppose charging for the use of public streets. This is the time to establish the principle and use it to avoid the nightmarish scenario of total gridlock.”