More than 60% of drivers would find it acceptable if their vehicle provided an audible and visual warning when they exceeded the posted speed limit, according to the results of a new Insurance Institute for Highway Safety (IIHS) survey.

Nearly half of the 1,802 drivers surveyed said they wouldn’t mind vehicle technology that makes the accelerator pedal harder to press or automatically restricts speed.

“These findings are exciting because they suggest American drivers are willing to change how they drive to make our roads safer,” said IIHS President David Harkey, in a news release. “The conventional wisdom has always been that speed-restricting technology would never fly in our car-centric culture.”

Speeding is consistently a factor in more than a quarter of U.S. traffic fatalities, IIHS said. In 2022, the latest year for which numbers are available, that amounted to more than 12,000 deaths; yet nearly half of drivers admit to traveling at least 15 mph over the limit in the past month, according to the AAA Foundation for Traffic Safety’s 2023 annual Traffic Safety Culture Index (TSCI) survey.

Crash data released by the National Highway Traffic Safety Administration in May shows 18% of all drivers involved in a fatal crash in 2022 were speeding at the time of the crash. It also says speeding was related to 29% of all fatal crashes during that time period. Overall, 12,151 people died in speed-related crashes in 2022; a slight decrease from the 12,498 killed in 2021, according to NHTSA’s data.

“We can no longer pretend this is an unsolvable problem,” said IIHS Senior Research Scientist Ian Reagan, who designed the survey about intelligent speed assistance (ISA). “With the technologies we have now, we could stop virtually all speeding and eliminate speeding tickets to boot. Instead, we seem to be going the opposite direction, with adaptive cruise control and partial automation systems that allow drivers to peg their speed at 90 mph if they want.”

Speed limiters have been around for years, but the conventional type only allows one maximum setting, meaning the few fleet operators and others who use them have to set the maximum at highway speeds, making them useless on most U.S. roads, IIHS said.

ISA systems use GPS and a speed limit database, sometimes together with cameras capable of reading posted signs, to identify and adapt to the actual speed limit, the release states. For example, an icon with the local speed limit that appears in the corner of Apple Maps, Google Maps, and Waze apps is a simple version.

“More robust ISA systems sound a warning or flash an alert when the driver exceeds the limit — or when they exceed it by more than a specific amount,” IIHS said. “Others provide accelerator feedback — making the pedal harder to push — or restrict power to the engine to prevent the driver from going too fast.

“As of next month, the European Union will require all new vehicles to be equipped with ISA systems that at least give audible or visual warnings, though drivers will be able to turn the systems off.”

According to the European Commission, speeding contributes to around 30% of fatal crashes with 40-60% of drivers exceeding the limit. Results from a wide range of studies indicate that reducing average speeds by just 1km/h can result in a 5% reduction in fatal crashes, the commission says on its website.

To account for how respondents’ driving style might influence their feelings about ISA, Reagan posed general questions about the danger of speeding, the effectiveness of technology, and individual driving behavior.

Drivers of all types were randomly assigned to three groups. One group was asked about ISA that provides an advisory warning, another about ISA that makes the accelerator harder to press, and a third about ISA that restricts acceleration when the vehicle exceeds the speed limit.

In the research context, IIHS defined “acceptability” as whether respondents would want to have the option to use a feature or product that they have never experienced before. Acceptability is then calculated based on the answers to various questions rather than a single “yes” or “no” question.

Any version of ISA likely to be adopted in the U.S. would give drivers the option to switch it off, so it will only be beneficial to the extent that the public finds it acceptable, IIHS said.

Sixty-four percent of respondents in the warning group, 50% in the accelerator feedback group, and 52% in the restricted acceleration group found the type of ISA they were asked about acceptable.

Regardless of group, more than 80% of all drivers agreed or strongly agreed that they would want a feature that displayed the current speed limit. More than 70% of all drivers also agreed or strongly agreed that they would like to hear an unobtrusive tone when the speed limit changes.

There was a clear preference for advisory systems over those that control the vehicle’s speed.

Nearly 60% of drivers in the advisory-only group agreed it would be acceptable if the ISA system came on automatically at the beginning of every trip compared with 51% of drivers in the accelerator-feedback group, and 48% of drivers in the speed-limiter group.

Sixty-five percent of drivers in the advisory group said they would want their next car to have ISA if most other vehicles had it, compared with 51% and 52% for the other two groups. Similar proportions said it would be a good idea for ISA to be required in all new cars.

Around 70% of drivers in all groups agreed they would want ISA in their next car if their insurance company lowered their premiums based on evidence that they don’t speed.

The percentages who agreed that ISA would be acceptable to them also increased across all groups if the feature intervened at 10 mph over the posted limit, compared with 1-2 mph over. Nearly 80% of the advisory-only group and more than half of the other two groups said the feature would be acceptable if it had a 10 mph tolerance.

For example, the standard set by the EU requires warnings to start when the vehicle speed matches the speed limit for six seconds and after 1.5 seconds when the vehicle exceeds the posted limit by any amount. The survey suggests that if the U.S. adopted the same standard, more drivers would switch off the feature.

Frequent speeders were 20% less likely to accept ISA than occasional or rare speeders, suggesting those who need it most might use it the least, IIHS said.

However, the two groups would be nearly equally likely to keep the feature switched on if their vehicle had it. Perhaps that means frequent speeders recognize that the system would be useful to them, though they have mixed feelings about it, IIHS concluded.

Overall, about half of the drivers in the accelerator-feedback and speed-limiter groups said they would frequently override the feature.

Based on the survey results, IIHS thinks a federal mandate could help overcome ISA resistance.

“Past research has shown that drivers worry about irritating other motorists if they drive slowly, and the surveyed drivers were more likely to say they would accept ISA if most other vehicles had it.

“U.S. regulators could also make the feature more attractive — and more likely to be used — with design elements that are missing from the EU’s requirements. U.S. drivers might be more apt to accept a system that allowed a higher tolerance on interstates and freeways but had a lower threshold in school zones and other areas with many pedestrians and bicyclists.”

Harkey added, “This technology enables nuanced interventions that were never possible in the past. The next challenge is to encourage automakers and drivers to embrace it so we can begin saving lives.”

In May, the California Senate passed a bill that would require 50% of passenger vehicles, motortrucks, and buses sold in the state to be equipped with a speed assistance system by the 2029 model year and all vehicles by the 2032 model year.

According to the bill, the assistance system would use GPS data to monitor speed limits. If the system determines a vehicle is traveling at 10 miles per hour over the speed limit, a one-time visual and audio signal would alert the driver.

Emergency vehicles would be exempt from having the system.

The National Transportation Safety Board (NTSB)’s investigation of a 2022 multi-vehicle collision in North Las Vegas, Nevada prompted the board last year to recommend ISA technology be required in all new vehicles.

“This crash is the latest in a long line of tragedies we’ve investigated where speeding and impairment led to catastrophe but it doesn’t have to be this way,” said NTSB Chair Jennifer Homendy, in November 2023. “We know the key to saving lives is redundancy, which can protect all of us from human error that occurs on our roads. What we lack is the collective will to act on NTSB safety recommendations.”

In December, IIHS and other Road to Zero Coalition members came together to advocate for the use of ISA and speed limiters to curb speeding-related deaths. The coalition is managed by the National Safety Council and includes dozens of members in the public and private sectors.

The call to action came just days after the release of the AAA Foundation for Traffic Safety’s  2023 TSCI survey, which found 1 in 5 drivers speed.

Images

Featured image: An aftermarket intelligent speed assistance device from Sturdy Corp. (Provided by IIHS)