Increased speed limits have killed nearly 37,000 people over the last 25 years, according to new research by the Insurance Institute for Highway Safety. While experts remain concerned about traffic crash deaths caused by alcohol, cellphone use and drugged driving, speeding is a significant safety crisis on American roads. In 2017 alone, about 1,934 were killed because of increased speed limits, IIHS found. “Every time you raise speed limits, you see more deaths,” said IIHS vice president for research and statistical services Charles Farmer, who conducted the study. “Sure, you save a little bit of time driving, but there’s this trade-off that you have to admit is there and decide whether or not it’s worth it.” The study concluded that a 5 mph increase in the speed limit causes an 8% increase in death rates on interstates and freeways. It causes a 3% increase in deaths on other roads.