Mims has served as a transportation expert in government and the private sector for more than 35 years in the areas of multi-modal transportation and aviation.
Currently, he serves as the transportation and infrastructure advisor to the Mid-Atlantic Laborers' Employers Cooperation and Education Trust (LECET), a group that advocates the interests of labour and management in the transportation and infrastructure construction sector.
He also served as vice president and aviation market leader for the engineering firm Parsons Brinckerhoff and was senior associate for the transportation group at Booz Allen Hamilton.
During his career, Mims held various leadership positions at the US Department of Transportation, Federal Aviation Administration and as a key staff member for Congressmen John Lewis of Georgia and Julian Dixon of California in the area of transportation, and as a congressional liaison for the Smithsonian Air and Space Museum and the National African American Museum.
Mims serves as a member of the board of directors and legislative advisor to the conference of minority transportation officials, member of the board of directors for the Central Maryland Regional Transportation Authority, former board member for the Airport Consultants Council, and former board member of the Maryland Transportation Authority.