The adoption of autonomous vehicles, or self-driving cars, in the District of Columbia could foster economic growth, but this change could also increase congestion, says a new report prepared for DC Sustainable Transportation.

The report sent from the mayor’s office to the chair of the city council last week highlighted the potential benefits of autonomous vehicles such as improved transportation accessibility and less space devoted to parking. Potential drawbacks, the report says, include pollution and congestion.

“The study forecasts that the additional VMT [vehicle miles traveled] in the future will be generated by individuals who were previously traveling by other modes now traveling by autonomous vehicle and empty vehicles relocating themselves,” said Mayor Muriel Bowser, in her letter to Chairman Phil Mendelson. “To mitigate this rise in VMT and increased congestion, the study recommends interventions and incentives to support shared rides and alternative modes of transportation.”

These recommended interventions include dedicated high-occupancy vehicle (HOV) lanes and congestion pricing. The technology could also decrease the total number of vehicles needed, the report says.

Bowser called the report “the first step to understanding the prospective adoption trajectories of autonomous vehicle technology.” The report makes several policy recommendations to be implemented in the next three years.

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