An accident early Thursday morning on Interstate 35 northbound snarled traffic this morning for hours for Hays County commuters. Around 1:40 a.m., an oil tanker flipped over and ended up in the ditch close to the access road just south of Slaughter Lane in Travis County, spilling an estimated 700 gallons of fuel. No other vehicles were involved in the crash. All lanes on the highway and the access road were shut down while crews cleaned up the area. The driver was transported to the Brackenridge Medical Center with minor injuries. The Austin Fire Department was able to stop the flow of gas from the tanker. I-35 travelers were diverted onto either Toll Rd. 45 (at no charge) or 1626 north; many faced miles of slow-moving traffic. To top it off, another minor accident at the intersection of 1626 and 967 in Buda caused more headaches for those drivers who had already gotten off the interstate. Heavy fog early in the day did little to help the situation. Officials reopened the northbound lanes of I-35 before 9 a.m., but the access road is expected to be closed for much of the day.