Powell is scheduled to start April 23, and will earn $120,827 a year.
Powell previously served as the chief executive officer of the Central Maryland Regional Transit Corporation, in which he oversaw a transit system with a ridership of more than two million passengers.
The transportation office was formed last year to elevate transportation as a priority in the county. The Department of Planning and Zoning previously oversaw transportation operations.
Before joining the CMRT in 2009, Powell founded an advanced technology vehicle manufacturing company called EV America.
Powell's experience also includes 12 years as executive director of the Advanced Transportation Technology Institute and various positions with the Worcester Area Transportation Corporation, Queen City Metro, Indianapolis Public Transportation Corporation and Southeastern Michigan Transportation Authority.
In a statement, Powell said he hopes his "lifetime experience in public transportation" will benefit the county.
"I am excited to work closely with a county executive who understands the important role public transportation plays in supporting residents in our community and is dedicated to a regional and cooperative approach to strengthening services for all," Powell said in the statement. "Furthermore, I am very grateful to have the opportunity to work for the best county I have ever lived in personally, and a county whose reputation is second to none nationally."
The functions of the Office of Transportation include managing the county's transit and paratransit services, coordinating funding, establishing connections that promote the county's goals and objectives and overseeing Howard Transit, HT Ride, Works on Wheels and Rideshare Coordination programs.
"John's extensive knowledge of the principles, practices and operation of fixed-route and paratransit systems made him a prime candidate for this position," Ulman said in a statement. "I am confident that John's years of directing transit services and planning organizations will make him a true asset to the county and its new Office of Transportation."