Jay Walder, the former Metropolitan Transportation Authority chairman who led a turnaround of Citi Bike, is stepping down as chief executive of the bike-share operator's parent company, Motivate. The move had been rumored in the bike-share community ever since ride-hail giant Lyft announced in early July that it was acquiring the Brooklyn-based company.

Motivate, which is being renamed Lyft Bikes, is the largest bike-share operator in the country by a wide margin, with franchises in San Francisco, Chicago, Boston and Washington, D.C., among others.

"As we approach the finish line in Motivate's acquisition by Lyft, as planned I am stepping down as CEO at the end of the month," Walder wrote in an email obtained by Politico. He added that he would be working as an adviser to Lyft after the deal closes and pursuing "new opportunities in the future of transportation."

Launched in 2013, Citi Bike was popular with New Yorkers yet in financial and operational trouble when Walder took over the following year. He re-energized the program with new software and bicycles and an expansion that eventually doubled the number of bikes in the system to 12,000.

The company was criticized, however, for failing to sufficiently extend operations into the outer boroughs and low-income communities. In the past year, fans of dockless bike-shares have argued that Citi Bike's stationary-dock system has made expansion time-consuming and expensive and could be better achieved by new bikes that self-lock and can be located via GPS tags.

In recent months Motivate has launched a dockless Citi Bike that is part of a pilot program taking place in the outer boroughs. The company also has rolled out a pedal-assist e-bike model that will have a starring role in helping alleviate congestion during the L-line shutdown.