A semi driver suffered minor injuries when his truck rolled while merging onto I-35 north from Highway 30 near Ames Tuesday. Authorities say Tim Waters of Jefferson was treated at Mary Greeley Medical Center after the incident that backed up traffic for about two miles. It took about three-and-a-half hours to clear the interstate. Authorities closed the west lane of northbound I-35 and diverted oversized loads to eastbound Highway 30 after the crash. An Iowa DOT traffic camera showed the semi tipping over as it was going too fast while trying to merge. The DOT says about a thousand gallons of herbicide spilled from the truck. It's not considered hazardous.