Objective: Previous studies on factors affecting drivers' decisions to use their mobile phones while driving are mostly focused on psychological and sociocultural contexts. Few investigations have been carried out on the role of traffic circumstances on drivers' decisions to use or not to use a mobile phone.
Methods: In this research, the effects of headway distance, speed, and the type of road as well as individual variables including age and driving experience are investigated. Forty-two subjects participated in observing 24 scenarios in a driving simulator.
Results: Logistic regression models showed that car speed, headway distance, and age can predict whether drivers' answer an incoming call while driving. The results indicated that traffic circumstances at the onset of phone calls are stronger predictors of drivers' decisions to answer a cell phone compared to driver-related variables.
Conclusions: Headway distance and car speed can be used by in-vehicle information systems (IVIS) to warn drivers against using a mobile phone in certain traffic situations. Traffic safety campaigns for young drivers should focus on keeping safe headway distance and speed while driving.