Perhaps more surprisingly, about half of drivers say 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,” IIHS President David Harkey said. “The conventional wisdom has always been that speed-restricting technology would never fly in our car-centric culture.”
Speeding kills. It’s consistently a factor in more than a quarter of U.S. traffic fatalities. 2022, the latest year for which numbers are available, that amounted to more than 12,000 deaths. Yet about half of drivers admit to driving at least 15 mph over the limit in the past month, according to the AAA Foundation for Traffic Safety.
“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. That means that the few fleet operators and others who use them have to set the maximum at highway speeds, making them useless on the vast majority of U.S. roads.
In contrast, 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 little icon with the local speed limit that pops up in the corner of the Apple Maps, Google Maps and Waze apps is a simple version. (Waze and some other less well-known apps also offer additional ISA functions.)
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. 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.
To gain more insight into how American drivers would feel about ISA, Reagan conducted a survey of 1,802 drivers.
To account for how respondents’ driving style might influence their feelings about ISA, Reagan asked general questions about the danger of speeding, the effectiveness of technology and the respondents’ own 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.
The survey measured whether respondents would find the technology acceptable. In the research context, “acceptability” has a specific meaning. It’s meant to reflect whether a person would want to have or choose to use a feature or product that they have never experienced before, and it’s calculated based on the answers to various queries, 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.
In that respect, the survey results were encouraging. 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 want an unobtrusive tone to sound when the speed limit changes.
There was a clear preference for advisory systems over those that intervene to control the vehicle’s speed, however.
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.
Likewise, 65% 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.
The standard set by the EU is not that liberal. 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.
The survey flagged other potential pitfalls.
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. However, the two groups were about equally likely to say they would 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.
Overall, about half of the drivers in the accelerator-feedback and speed-limiter groups said they would frequently override the feature.
A federal mandate could help overcome resistance, the survey shows.
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.
“This technology enables nuanced interventions that were never possible in the past,” Harkey said. “The next challenge is to encourage automakers and drivers to embrace it so we can begin saving lives.”