Background Studies show that the use of cell phones while driving can increase the risk of crashes by up to four-fold; driver reaction times are increased by an estimated 0.5–1.5 s when talking on a mobile telephone. Although some states in Mexico have passed laws to limit cell phone use while driving, very little is known about its actual prevalence in Mexico.

Objective To quantify observed cell phone use by car drivers in three specific Mexican cities.

Methods Two rounds of roadside observations from a group of randomly selected automobile drivers were conducted in June–August 2011 and December 2011–January 2012 in Guadalajara-Zapopan, León and Cuernavaca. Multiple logistic regression analysis was performed to identify associated demographic and environmental risk factors.

Results A total of 7895 drivers were observed; 10.79% were using cell phone while driving. Cell phone use was highest in Guadalajara-Zapopan (13.96%; 95% CI 12.90 to 15.08), then Leon with (7.80% 95% CI 6.66 to 9.06) and lowest in Cuernavaca (7.42%; 95% CI 6.30 to 8.67). This prevalence remained stable in the two rounds of observations except for Leon where prevalence increased from 5.2 to 10.4 (p=0.000). Variables found to be associated with this risk were the sex (women), age (<18 years) and type of car (particular cars).

Contribution to the Field This information fills an important gap in knowledge regarding the use of cell phones while driving in the Mexican population. Authorities should use this information to design and evaluate specific, preventive interventions.