Following a review of engineering and traffic safety reports, the Idaho Transportation Board approved a plan on Friday to increase the speed limit on selected rural sections of interstates in southern and eastern Idaho in early August.

The maximum speed limit on sections of interstates 15, 84 and 86 will increase to 80 mph by early August, following coordination of sign installation. The speed limits do not increase until the new signs are in place.

The maximum speed for trucks will increase to 70 mph. 

The hikes were scheduled to take effect around the first of July, but were delayed for review.

While the speed-limit increase is in effect for rural sections of interstate, the speed limit in urban areas will not increase. Officials are continuing to study possible speed limit increases for sections of I-90.

Legislation allowing the Idaho Transportation Board to increase the speed limit was approved by the Idaho Legislature during the 2014 session. The new speed-limit law also allows for increases on non-interstate highways to 70 mph.

The law was signed by Gov. Butch Otter on March 18.