Drivers' health and fitness are essential issues in order to predict traffic crashes, taking into account that these characteristics are essential to perform this task correctly and safety. The purpose of this research was to analyze the frequency in which drivers who feel physically or emotionally unable to drive decide to perform this task, or not, under states of indisposition, as well as the perception of the effect that this indisposition had on driving. This cross-sectional study used a total sample of n=1200 (666 [56%] men and 534 [44%] women) Spanish drivers, who answered a questionnaire designed to collect data about their psychosocial characteristics, driving habits and perceptions about their driving performance and safety behaviors related with physical and mental health. The main selection criteria were to be in possession of any type of driving license for vehicles other than motorcycles and to drive frequently. The results showed that 62.5% of the participants that were not in perfect con- ditions to drive at times decided not to drive and 37.5% decided to use the vehicle. Furthermore, 16.5% of the starting sample experienced inappropriate psychophysical conditions while driving. In the group of drivers who decided to use the vehicle, 46.9% admitted that their driving was affected. It was determined that there is a substantial lack of correspondence between driver's perceptions and behaviors with respect to the impact of health conditions on crash risk, and a growing need to raise people's awareness regarding this fact. A large number of drivers continue driving even when they are not in condition to do so, which is clearly a risky behavior. It seems necessary to implement preventive actions and measures oriented to raise appropriate public awareness about the risks derived from driving under an altered physical or emotional state