Unsafe driving behaviour and four wheel drive vehicles: observational study.

OBJECTIVE To assess the level of compliance with the new law in the United Kingdom mandating penalties for using a hand held mobile phone while driving, to compare compliance with this law with the one on the use of seat belts, and to compare compliance with these laws between drivers of four wheel drive vehicles and drivers of normal cars. DESIGN Observational study with two phases-one within the "grace" period, the other starting one week after penalties were imposed on drivers using such telephones. SETTING Three busy sites in London. PARTICIPANTS Drivers of 38,182 normal cars and 2944 four wheel drive vehicles. MAIN OUTCOME MEASURES Proportions of drivers seen to be using hand held mobile phones and not using seat belts. RESULTS Drivers of four wheel drive vehicles were more likely than drivers of other cars to be seen using hand held mobile phones (8.2% v 2.0%) and not complying with the law on seat belts (19.5% v 15.0%). Levels of non-compliance with both laws were slightly higher in the penalty phase of observation, and breaking one law was associated with increased likelihood of breaking the other. CONCLUSIONS The level of non-compliance with the law on the use of hand held mobile phones by drivers in London is high, as is non-compliance with the law on seat belts. Drivers of four wheel drive vehicles were four times more likely than drivers of other cars to be seen using hand held mobile phones and slightly more likely not to comply with the law on seat belts.