While the boost is set to take effect July 1, it may take a long time for the Virginia Department of Transportation to implement the increase, according to reports by The Roanoke Times.
The publication says the DOT will have authority on when and where to implement the increase, and a decision could take four months or longer.
The DOT plans to analyze each eligible road as well as traffic, accident and law enforcement numbers, The Roanoke Times reports.
"These studies will take time, and recent staff reductions may slow down progress," Jason Bond, a VDOT spokesman in the Salem District, told the publication.
In the meantime, the speed limit on Interstate 81 will stay at 65 mph, with the exception of segments where it is posted at 60 mph.
According to the bill, eligible roads would include interstate highways, multilane, divided, limited access highways, and high-occupancy vehicle lanes if such lanes are physically separated from regular travel lanes.