Officials in Idaho, where the totality path crossed the center of the state, began planning for the eclipse a year in advance. The state Transportation Department suspended construction projects along Interstate 15, which traverses Eastern Idaho, from August 18–22 in order to have all lanes open; their counterparts in neighboring Utah, where many were expected to travel the north via the highway from the Salt Lake City metropolitan area, did the same. On the morning of the eclipse, many drivers left before dawn, creating traffic volume along I-15 normally not seen until morning rush hour; northbound traffic on the interstate in Box Elder County north of Salt Lake City slowed to . The Idaho State Police (ISP) stationed a patrol car along I-15 every between Shelley and the Utah border.