In 2015, six hundred and sixty thousand drivers in the United States were estimated to use cell phones each day, while driving behind the wheel during daylight hours.
Cell phone use while driving has become a leading cause of vehicle crashes over the last two decades.
The study found that the overall relative risk (RR) of having an crash for cell phone users when compared to non-cell phone users averaged 1.38 across all groups.
When adjusted for distance driven per year and other crash risk exposures, RR was 1.11 for men and 1.21 for women.
Many jurisdictions have enacted laws to ban handheld mobile phone use.
Nevertheless, many jurisdictions allow use of a hands-free device.
When drivers talk on cell phones the risk of an automobile crash resulting in hospitalization is four times higher than when not talking on a cell phone The Société de l'assurance automobile du Québec (SAAQ), the provincial automobile insurance association in Quebec, conducted a study on driving and cellphones in 2003.
Questionnaires were sent to 175,000 drivers and analysis was done on the 36,078 who responded.
The questionnaire asked about driving habits, risk exposure, collisions over the past 24 months, socio-demographic information, and cell phone use.
Questionnaires were supported with data from cell phone companies and crash records held by police.