BOISE -- Motorists can now legally drive 80 miles per hour on some stretches of Idaho interstate.
Idaho Transportation Department workers began replacing signs along Interstate 84 this morning.
The change affects rural stretches of interstate 15, 84 and 86.
Truck speeds will increase to 70 mph.
The change will not affect the state's more urban sections of highway, including I-84 between Boise and Caldwell as well as roads through Pocatello and and Idaho Falls. Those sections will stay at 65 mph even after the increase.
Northern Idaho's roads will not see an increased speed either.
Lawmakers voted to allow faster speeds on Idaho roads during the 2014 legislative session, but ultimately left the decision up to ITD. The department conducted safety studies and engineering reviews during May and June before giving drivers the green light.
The speed limit change does not go into effect until signs are posted in that area. ITD officials say they hope to have all the new signs put up today, but some areas could be delayed.
The last time the interstate speed limit was increased across Idaho was in 1996, when it was raised from 65 mph. Limits were raised from 55 mph to 65 mph in the 1980s.