How closely linked are speeding and cellphone use behind the wheel? Closer than researchers from Insurance Institute for Highway Safety originally thought.
“Until now, safety experts believed drivers used their cellphones most at slower speeds,” said IIHS President David Harkey. “But data from safe-driving apps show that, in free-flowing traffic, the opposite is true.”
IIHS researchers looked at nearly 600,000 car trips from July to October 2024 across the United States. They found that phone use while driving on freeways and other “limited-access roads” increased 12% for every 5 mph over the speed limit.
On surface roads, the researchers observed a 3% increase in phone use for every 5 mph over the speed limit.
“It’s alarming that the relationship between cellphone manipulation and speeding was the strongest on roads with the highest speed limits,” said Ian Reagan, study author and IIHS senior research scientist.
Some possible reasons are increased risk-taking by certain drivers and stress.
“Earlier research shows phone use spikes during rush hour and school drop-off, and those same situations may also lead people to speed,” the institute said.
IIHS recommends that police and law enforcement look at ways to curb both risky behaviors.
“Speeding and distracted driving together are especially dangerous,” Harkey said. “This research shows the risk is greater than we once thought, but it also points to an opportunity to address both problems at the same time.”
