Cell phones have become a major problem for modern roadway safety. Distracted driving accounted for over 3200 deaths in 2024, representing around 8 percent of all fatal crashes in the United States, and a new study published Tuesday by the Insurance Institute for Highway Safety indicates that the issue is more dire than initially thought.
Previously, safety experts believed drivers used their cellphones most at slower speeds, IIHS President David Harkey said. However, nationwide telemetry data provided by car insurance companies reveals that speeding and cell phone usage are actually linked behaviors. The more drivers exceeded the speed limit, the more they handled their phones.
“It’s alarming that the relationship between cellphone manipulation and speeding was the strongest on roads with the highest speed limits,” said Ian Reagan, the IIHS senior research scientist who wrote the study.
The strongest concurrent speeding and phone usage rates were observed during freeway driving. Driving time spent handling a phone rose by 12 percent for every 5 mph drivers went over the local speed limit on freeways. Cell phone usage increased by 9 percent for every 5 mph over the speed limit drivers went on freeways with 70-mph limits. By comparison, roads with 25-30 mph posted speed limits saw less correlation between speeding and phone use.
The type of road plays just one part in the connection between cell phone use and speeding. Previous research shows that phone use spikes during rush hour and school drop-off. Reagan told Road & Track that evidence exists for environmental influences playing into people’s driving decisions. As a result, certain times of day and driving situations that are perceived as safer often account for increased rates of speeding and cell phone use. Similarly, previous studies focused on driving and phone use often relied on small groups of volunteers, skewing the data to a small sample size. Modern studies rely on data collected by safe-driving apps offered by insurers as a means to lower premiums.
“These apps, which promise cost savings for drivers who enroll, let insurers adjust premiums based on how each person drives. Using a smartphone’s GPS and other sensors, the apps track speed and location, time of day, events like hard braking and rapid acceleration, and phone use. With large amounts of aggregated data, researchers can now measure phone use much more comprehensively than before,” the report reads.
IHS Senior Statistician Sam Monfort analyzed nearly 600,000 trips taken between July and October 2024 by drivers across the United States, excluding Alaska, California, Hawaii, and New York, to complete this study. The data was provided by Cambridge Mobile Telematics, which operates safe-driving apps tied to passenger-vehicle insurance. Trips had to be longer than 18 minutes and with at least two minutes on the interstate to be included. Drivers were counted as handling their phones when the phone’s internal gyroscope detected a significant rotation while the screen was unlocked. Additionally, to identify speeding, telematic data was matched with GPS location to a speed-limit database.
With so much data available on dangerous driving habits, IIHS officials are naturally advocating for increased enforcement in specific situations. Cell phone enforcement is usually focused on visual identification by law enforcement at stoplights or on slower roads. However, the study says that curbing distracted driving and speeding could actually be a one-two punch, particularly if approached from a behavioral and technological standpoint.
“[Enforcement] is typically siloed into either focusing on speeding or focusing on distraction, but this points to a lot of value in coming out with patrols that are really targeting both,” Reagan said. “Also, we’re really big proponents of safety cameras, and there is safety camera technology that’s able to discriminate cell phone use. The typical way that a police officer would enforce distracted driving has a lot of limitations to it.”
A New York transplant hailing from the Pacific Northwest, Emmet White has a passion for anything that goes: cars, bicycles, planes, and motorcycles. After learning to ride at 17, Emmet worked in the motorcycle industry before joining Autoweek in 2022 and Road & Track in 2024. The woes of alternate side parking have kept his fleet moderate, with a 2014 Volkswagen Jetta GLI and a BMW 318i E30 street parked in his Queens community.
