Excessive speed is a contributing factor in approximately one-half of all traffic fatalities.  Approximately 10,000 people are killed each year in speed-related car accidents in the United States.  That number has been increasing, as speed limits have increased across the country in the past 25 years.  Some argue that increasing speed limits simply acknowledges the reality that most drivers exceed the speed limit.  However, studies show that, once the limit is raised, drivers just go faster.  Most states have maximum speed limits of 70 miles per hour.  Six states have 80 mph speed limits.  Texans can drive up to 85 mph on some highways.

A study from the Insurance Institute for Highway Safety (IIHS) concluded that increased speed limits have cost 40,000 lives over the past 25 years, including approximately 2,000 in 2019 alone.  The study also showed that each 5 mph increase in the speed limits results in an 8 percent increase in highway fatalities.

Charles Farmer, IIHS vice president for research and statistical services, noted that a 5 mph increase in speed saves only 6 ½ minutes on a 100-mile trip.  “Before raising speed limits, state lawmakers should consider whether that potential time savings is worth the additional risk to lives,” Farmer says.

“There are huge benefits from reducing speed, said Veronique Feypell, manager of the Road Safety Program at the International Transport Forum.  According to Feypell, a 10 increase in speed leads to a 40% increase in the likelihood of a fatal crash.

Researchers are investigating  new approaches to addressing the issue of vehicle speed, including a geofencing approach that would automatically reduce vehicle speeds in certain areas.  Urban planners are also experimenting with reduced speed areas that encourage more pedestrian and bicycle use.

Climate change is another factor that is making planners consider reducing vehicle speed in urban areas.  Driving at lower speed means less fuel use, which lowers carbon emissions.  “There are 1.3 million traffic deaths annually and another 4.2 million deaths attributed to pollution,” said Janette Sadik-Kah, former commissioner of the New York City Department of Transportation and chair of the Global Designing Cities Initiative.  “Streets that are safe for people also support the health of the planet.”