The cellphone, a source of distracted driving, could also be a tool to fight it

But there are ways drivers can use cellphones to improve safety, and the ubiquity of cellphones could be part of their appeal as a distracted driving solution.

IIHS has tested a feature that uses an aftermarket windshield-mounted camera for forward-collision warning. In the 2016 model year, 40 percent of U.S. vehicle series offered forward-collision warning with automatic emergency braking, and 21 percent offered forward-collision warning without automatic emergency braking.

Reagan says similar technology could be employed using the outward-facing smartphone camera and could have a huge impact — in cars that lack automatic emergency braking, forward-collision warning still reduces rear-end striking crash rates by 27 percent.

The smartphone would be placed on the dashboard with the camera facing ahead, and an app would detect whether vehicles in front are too close. The phone would then issue a warning.

Insurance companies such as Progressive provide phone applications that collect driver data as part of usage-based insurance programs. These programs, aimed at encouraging safer driving, collect information about speed, time of day, phone usage and braking patterns.

The popular navigation app Waze allows users to opt in to alerts if the driver reaches the maximum speed limit.

But while the technology has potential, some features are not available or not widely adopted.

The industry is further from using the inward-facing smartphone camera for driver monitoring, said Reagan, in part because of driver privacy concerns. That technology tracks driver eye movements to issue warnings or shift displays when a driver appears to be distracted.

“I think that’s a big roadblock to getting driver-facing cameras accepted,” Reagan said, which “to me has incredible potential just because of the connection between visual distraction and serious crashes.”

Companies also have to sort through calibration issues as drivers take phones in and out of the car.

Wider use of an existing tool — the Do Not Disturb feature — could also improve safety.

It is built into Android and Apple cellphones. During device setup, Apple asks users if they would like to automatically block calls and notifications while they are driving.

IIHS found that only one-fifth of users opt in to that functionality while driving.

Automakers say that they are aiming to create greater voice control capabilities and infotainment centers integrated with the car’s functions. If drivers can control hardware features including climate control and phone functions, such as making calls, effortless manipulation of the car will reduce distraction.

Organizations including the National Transportation Safety Board, NHTSA, the National Sheriffs’ Association and Google serve on the National Distracted Driving Coalition steering committee. That coalition released a research paper in March about technology’s role in reducing driver distraction, but it focused mostly on native systems such as internal driver-monitoring cameras.

Regulatory decisions in Europe have pushed automakers to equip vehicles with driver-monitoring systems, and in the U.S., automakers include the technology as part of driver-assist systems.