IIHS says its study of CMT data show police undercount pre-collision phone use

The Insurance Institute for Highway Safety (IIHS) says its new study, based on anonymized cellphone data from Cambridge Mobile Telematics (CMT), shows that more drivers use cellphones before crashes than police reports reflect.

The telematics data, collected from safe-driving apps that drivers voluntarily enroll in, show that police reports undercount phone use before crashes by a factor of at least seven, according to IIHS.

“It’s widely accepted that police reports often fail to capture the role of cellphones in crashes. Many smartphone functions are hard for a witness to see, and drivers are reluctant to admit being distracted,” said IIHS President David Harkey in a press release. “Telematics are allowing us to understand the true magnitude of the problem.”

IIHS says that, according to CMT data its researchers examined, drivers enrolled in safe-driving programs that rely on the CMT platform used their cellphones in the 30 seconds before impact in 7% of single-vehicle crashes and 8% of two-vehicle crashes. Police reports for the same crashes recorded phone use in less than 1%. Both include drivers whose screens were unlocked for any reason, including navigation.

“However, telematics data show the problem of undercounting is nearly as severe when only physical manipulation of the phone and hand-held and hands-free calls are considered,” IIHS states in the release.

“Anything that takes the driver’s focus away from driving — including eating, talking or even daydreaming — increases crash risk. But the risk is more severe for more complex tasks that take the driver’s eyes away from the road. Looking away from the road for just 2 seconds doubles the risk of a crash or near-crash event.”

IIHS notes that telematics data offer “no way of knowing how long drivers in the study sample spent looking at their unlocked screens before they crashed — if they were looking at them at all.”

“It’s also impossible to know how many additional drivers were using similar apps with CarPlay or Android Auto,” the release states. “Such use does not require the phone’s screen to be unlocked. Even when police and telematics both indicated cellphone use, they usually didn’t agree about the type of use. Police reports noted the same activity as the telematics data in only three out of nearly 17,000 linked crashes.

“That mismatch could be one key to the broader problem of underreporting. Police officers may not always be able to determine exactly how a driver was using a cellphone after a crash. That challenge is compounded by the fact that in many jurisdictions, only certain types of cellphone use are illegal. But if other, legal behaviors go unreported, lawmakers may be slow to realize that they also increase crash risk. Telematics data could help address that disconnect.”

According to IIHS, 21 states now prohibit drivers from holding phones, meaning all a police officer needs to see is a phone in a driver’s hand to enforce the law, rather than what the driver is doing on the phone. And IIHS says its research shows the “more sweeping laws” are more effective.

To determine how often smartphone use is overlooked in police reports, IIHS researchers worked with CMT to link crashes recorded by safe-driving apps to police-reported crashes in four states between 2021 and 2024, the release states.

“Since police reports do not always record crash times and locations with perfect precision, crashes that occurred within the same 15-minute window and within the same one-mile radius were determined to be a match,” the release states. “This generated a sample of nearly 17,000 linked crashes.

“Along with detecting crashes, CMT’s platform can identify when and how the driver uses their phone. To monitor distraction, the company tracks hand-held calls, hands-free calls, and manipulation or handling of the device. It also logs times when the screen is unlocked for something passive like Google Maps or YouTube, though CMT does not use this measure in its own studies of distraction.”

The release notes that CMT doesn’t track the specific apps that are used, and researchers didn’t have a way to determine whether the phone user was at fault in the crash or whether distraction caused the incident.

“Looking only at active cellphone use, the researchers found that drivers tapped, swiped, or otherwise manipulated their phones before hundreds of crashes, while hands-free and hand-held calls were comparatively rare,” the release states. “Police reports noted almost none of this activity.”

IIHS says for a more complete picture, the researchers also looked at how often the telematics data and police reports noted passive cellphone use.

“For the telematics data, this meant any time that the driver was not touching the device, but the screen was unlocked,” the release states. “The police report categories used for comparison were broader and included behaviors such as ‘other activity with an electronic device,’ ‘other electronic device — navigation, radio, etc.,’ and ‘cell/mobile device use — unknown.'”

As shown in the table below, passive use was about as common as active use in the 30 seconds before impact:

Researchers concluded that navigation apps may have accounted for much of that passive activity.

“In a U.S. Department of Transportation study that tracked drivers during their everyday trips, many of the longest glances away from the road before crashes and near crashes were directed toward the center stack, a common location for cellphone mounts,” IIHS states in the release.

However, IIHS says nearly 25% of drivers who participated in a separate IIHS survey admitted to watching a video on their phone while driving at least once in the previous 30 days.

IIHS researchers also found a trend toward screen-based smartphone apps, like social media and games, as new temptations.

“The apps may be new, but the danger isn’t,” said Aimee Cox, IIHS research scientist and the study’s lead author, in the release. “Any phone use that takes a driver’s eyes off the road can increase crash risk.”

Driving on the upcoming Labor Day holiday also “comes with added risk,” according to CMT.

A CMT press release states that, according to the National Highway Traffic Safety Administration (NHTSA)’s Fatality Analysis Reporting System (FARS), Labor Day averaged 116 fatal crashes from 2020 to 2024. That’s reportedly 12% higher than crashes recorded on a typical Monday.

Fatal crashes involving speeding are also 36% higher on Labor Day, CMT says.

Distraction, speeding, and high-speed distraction increase on Labor Day, with some of the biggest spikes occurring during morning and afternoon travel, the release states.

CMT found:

• • Drivers spend 8.5% more time interacting with their phones on Labor Day than on a typical Monday, up from 1 minute and 43 seconds to 1 minute and 52 seconds per driving hour.
  • Distracted driving is highest in the late afternoon from 3-5 p.m., when drivers spend 11.1% more time on their phones than on a typical Monday.
  • Drivers speed more on Labor Day, spending 34% more time speeding than on a similar Monday, which doubles from 7-9 a.m.

Images

Featured image provided by IIHS