A man makes his way through the District on a rental scooter on May 3. (Bill O'Leary/The Washington Post)

Bird, one of the nation’s largest providers of shared scooters, is making the case to D.C. Mayor Muriel E. Bowser (D) that capping fleet sizes is counterproductive to her sustainability goals.

The District last week unveiled new regulations that limit scooter services to a maximum of 600 vehicles and require them to deploy scooters with capability for a maximum speed of 10 mph. Under rules set to go into effect in January, e-scooter companies also will need to offer a cash payment option to customers and pay fees to the city.

“The regulations are antithetical to Washington D.C.’s climate plan, and its long-standing history as a leader in sustainability,” David Estrada, head of government partnerships at Bird, said in a letter to Bowser this week. “While the city works to make progress toward meeting its ambitious goal of cutting greenhouse gas emissions by 50 percent by the year 2032, it threatens to advance a set of policies that stifle solutions that have proven to be helpful in achieving that goal.”

Scooters are one of the solutions to taking vehicles off the road because they can replace cars for short trips, he said. Estrada wrote that more than 580,000 miles have been ridden on Bird scooters since they arrived in the District six months ago, which “helped the city avoid over 516,000 pounds of carbon emissions from entering the atmosphere had those trips been otherwise taken by car.”

In announcing the new regulations last week, the District Department of Transportation said the requirements signal Bowser’s commitment to “fostering innovation” and delivering “the safest, most sustainable, and most efficient transportation options to District residents and visitors.” Bowser’s office responded to Bird’s letter with a statement late Tuesday that said the program “is expanding in a way that addresses the needs of users and the concerns of residents" and said her administration “is committed to embracing technology that provides more transportation options that reduce the impact of emissions on our environment.”

The city is allowing the companies to increase the number of scooters in their fleet to 600 from 400. The companies can then request their fleet be increased up to 25 percent after an evaluation by DDOT. Companies that meet performance measures, and maintain safe and quality operations, could be operating up to 1,200 scooters in the city by the end of 2019.

“We think that is a fairly substantial expansion,” said Sam Zimbabwe, a top DDOT official who has been overseeing the program. He said he understands the companies' position to want the fleet cap removed, but he said the city’s approach responds to both their calls for expansion and residents' concerns about safe operations. DDOT also wants to keep the program competitive, he said, to allow more companies to enter the market rather than limit the number of providers with an expanded fleet size.

“We are committed to making this program work,” Zimbabwe said.

In addition to Bird, three other companies — Lime, Skip and Lyft — also operate in the city. Spin plans to launch its scooter services in D.C. after suspending its bike-share operations this summer. JUMP operates electric bikes.

A survey of Bird riders in the District found that nearly 90 percent use Bird to get to work, run errands or commute to school. And about one of every four users rides scooters to connect to public transit. A great majority of users — 90 percent — said they want more Birds on the road, Estrada said.

Scooter companies have been lobbying the city to eliminate the fleet cap. Some say a city like Washington could need as many as 20,000 scooters and dockless bikes to serve all eight wards.

"The Department of Transportation’s proposed cap on e-scooters available to the people of D.C. eliminates any chance of this program being equitable, of solving issues related to transportation deserts in the city, and ultimately of getting more cars off the road,” Estrada said in his letter. “Critical to a successful e-scooter share program is convenience and accessibility.”

Capping the size leaves e-scooter providers little incentive to spread their fleet outside the most popular, high-density areas.

The city’s regulations, which also apply to bike-share providers, will require companies to have scooters and bikes in all wards of the city. But they will only be required to have at least six vehicles in each ward, which means companies are still unlikely to deploy significantly more vehicles to underserved areas east of the Anacostia River.

Bird also protested DDOT’s requirement that companies deploy scooters capable of reaching speeds no higher than 10 mph, while e-bikes can go up to 20 mph, saying the policy ignores research about e-scooter and bike safety that suggests a disparity in speed between vehicles using the same shared infrastructure will make the roads more dangerous.

“Vehicles traveling at significantly different speeds will create dangerous conditions, and could increase opportunity for collisions between cars, e-scooters, and bikes,” Estrada said. And, he said, there is no data to suggest that 10 mph is safer for e-scooter riders than 15 mph.

“We hope that you will consider intervening in the current process and work with us on defining a more practical solution to improving mobility options in the District,” he said.