Ronald Kirby, 69, the director of transportation planning at the Metropolitan Washington Council of ­Governments (COG), died Nov. 11 in Alexandria, VA. Authorities have ruled his death a homicide.

Kirby was one of the region’s leading experts on transportation planning. In a statement, COG’s Executive ­Director Chuck Bean said employees “are ­devastated by the loss of our colleague.”

Kirby, he said, was a “key figure in all aspects of our work on regional planning and collaboration. He guided the work of the Transportation Planning Board for more than 26 years.”

Kirby joined COG in 1987 and oversaw long-range ­planning for public highway and transportation systems in the D.C. region. Before joining COG, he directed the transportation program at the Urban Institute.

Kirby was from Australia.