The board voted 9-3 to remove Evans, who had held the job since October 2007. Gerald Ross, the department's chief engineer, was named interim commissioner.
"We needed to send a signal that we as a board are making a change in direction," said board member Steve Farrow.
Gov. Sonny Perdue and legislative leaders have been pushing a proposal that could gut the responsibilities of the board, which sets Georgia's $2 billion transportation budget. The bill's author says the state needs to speed up its road-building efforts.
Members of a Transportation Board committee declined several months ago to take action against Evans, who had been accused of sending personal e-mails on state computers while working for other state agencies.