The Lawrence County Highway Department said it will establish load limits on all paved roads that will be in effect until at least May 1.
Signs likely will be posted Monday. Weight will be limited to 6 tons per axle. Old Highway 14, west of Spearfish to the Wyoming line, will remain at 80,000 pounds gross weight.
Highway superintendent Dick Birk said most load limits will stay in place until May 1, but might be in effect longer at higher elevations.
Load limits are put in place to allow the frost to evaporate from the ground. Moist ground makes the roads more susceptible to damage from vehicles hauling heavier loads.