The drive to Mount Rushmore can go a little faster now.
South Dakota became the latest state to raise the speed limit Wednesday, allowing interstate drivers to travel up to 80 miles per hour.
States across the country have been raising their speed limits as lawmakers argue that roads and cars are safer. Idaho, Wyoming and Utah have already raised their limits to 80 mph; on one toll road in Texas, it's 85. Minnesota, where interstate limits are 70 mph, has started raising speed limits to 60 mph on 340 miles of highways.
But auto safety experts warn that with increased speed, comes increased crashes and fatalities. Already nearly one-third of motor vehicle fatalities are speed related, a figure that has remained constant for the past decade or so.
South Dakota House Majority Leader Brian Gosch said South Dakota already has good roads, and "with improved car and safety technology … it seemed like a reasonable step."
Most stretches of Interstate 90, which takes travelers from Sioux Falls to the Black Hills, and I-29, which goes to Fargo, already allow drivers to go 75 miles per hour. "It seemed like if I was doing 75, I was getting passed quite a bit," said Gosch, a Republican from Rapid City who championed the amendment. The higher limit, which garnered little legislative discussion, was folded into a transportation bill signed last month by Gov. Dennis Daugaard that raises the gas tax and vehicle registration fees to pay for road and bridge repairs.
Federal traffic safety regulators run crash tests at between 30 and 35 mph.
"When you get to speeds of 80 miles an hour, vehicles and safety features aren't built to protect people," said Anne McCartt, senior vice president of research at the Insurance Institute for Highway Safety, which runs its own crash test program.