Male drivers speed choice in Iran in relation to driver and front passenger characteristics

• Driver’s choice of speed in relation to vehicle’s occupants was studied.
• The age difference between drivers and front-right occupants and front-right occupant’s gender was investigated.
• If the front-right occupant is a close relative of the driver the speed decreases.
• If the front-right occupant is female the speed decreases.

Exceeding the speed limit is one of the most frequent traffic violations. Hence, many studies have investigated the factors affecting drivers’ choice of speed. To this end and with the cooperation of traffic police of the “Isfahan” province, and by residing in the freeways and multilane highways of this province, during several days the vehicles’ speed were measured, vehicles were stopped and the questionnaires were filled out. The number of occupants, the overall relationship between the occupants, gender, age and the relationship between the front-right occupant and the driver are the studied variables. The results of the statistical chi-squared test indicate that there is a significant relationship between the speed chosen by the driver, as the dependent variable, and variables related to the car occupants as independent variables. By increasing the number of occupants the speed chosen by the driver decreases. When the occupants are a family, and also when the front-right occupant is a close relative of the driver, the speed decreases. When the front-right occupant is a woman or has a big difference of age with the driver, the speed chosen by the driver decreases. This study showed that in addition to the common external controls, such as police surveillance and speed control cameras, occupants of the vehicles have an acceptable potential in making the drivers choose an appropriate speed.