MIT study confirms robotaxis don't reduce traffic

Waymo data reveals that the cars spend close to half of their time 'deadheading' — driving around with no passengers.

1 minute read

June 5, 2026, 5:00 AM PDT

By Diana Ionescu @aworkoffiction


A white Waymo SUV self-driving robotaxi in an intersection in Los Angeles, California.

A Waymo robotaxi in Los Angeles, California. | Karolis Kavolelis / Shutterstock

Like ridesharing, robotaxi companies promised that their services would reduce urban traffic congestion. And like ridesharing, data indicates that the industry did not keep this promise.

As Jonathan M. Gitlin explains in Ars Technica, a study published in MIT's Transport Findings shows that between 2021 and 2025 Waymo robotaxis spent between 36% and 56% of their time driving empty, a practice known as "headheading."

According to Gitlin, "A similar analysis conducted late last year on Waymo’s CPUC data from January 2024 through September 2025 by Matthew Raifman, who studies policy and autonomous vehicles at UC Berkeley, also found that 44 percent of Waymo’s miles were driven with empty vehicles and that two-thirds of those empty miles were robotaxis driving around waiting to be assigned a customer."

The numbers are similar in the ridesharing industry, "suggesting there’s little difference in congestion whether there’s a human behind the wheel or not."

Thursday, June 4, 2026 in Ars Technica

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