Lawmakers could boost highway speed limits

BOISE – Idaho lawmakers could adopt changes to allow the maximum speed limit on state highways to be raised to 75 mph from 65 mph and to eliminate a 65-mph limit for semi tractor-trailer drivers.

Transportation Department officials estimate 400 miles of roads could have speed limits boosted, with parts of Idaho Highway 75 between Twin Falls and Sun Valley and U.S. Highway 20 from Mountain Home to Fairfield qualifying. Sign changes would cost an estimated $12,000.

Interstate highway speed limits can already be raised to 75, such as the stretch of U.S. Interstate 84 between Caldwell and Fruitland on the Idaho-Oregon border.

Senate Bill 1133 would let the Idaho Transportation Department raise the maximum speed on stretches of smaller state highways where drivers are already driving that fast and where there hasn’t been an increase in accidents. If it passes, this would be the latest move in Idaho to boost speed limits that started after the mid-1970s when concerns over oil caused nationwide limits to be cut to 55.

“We will be using the same processes that are used nationwide for setting speed limits,” Transportation Department safety engineer Carl Main said, adding that decisions would be made in part on how fast traffic typically moves.

Idaho increased many of its highway speed limits to 65 mph in 1987.