While this is common behavior, has been found that mobile phone use while driving increases the risk of traffic accidents due to a decrease in driver reaction. To study the factors that define this behavior is important to refine policies to limit this. Using data from stated preference surveys implemented in Tunja (Colombia) was estimated a random coefficient model that explains why drivers use mobile phones while driving, using variables such as gender, old driving license, the speed reduction , importance of the phone call, travel Rev. Fac. Ing. Univ. Antioquia N.° 62 pp. 55-65. Marzo, 2012 * Autor de correspondencia: telefono: + 57 + 8 + 745 19 81, fax: + 57 + 8 + 742 21 74, correo electronico: luis.marquez@uptc.edu.co (L. Marquez)