Smoking bans in private vehicles

Smoking bans in private vehicles are enacted to protect passengers from secondhand smoke and to increase road traffic safety, e.g. by preventing the driver from being distracted by the act of smoking. Private vehicles are used by individuals for personal transportation; smoking bans in private vehicles are less common than bans extended to public transport or vehicles used during work, like trucks or police cars.

The acts of looking for, reaching for, and then lighting cigarettes can considerably distract the driver. A burning cigarette or marijuana joint that has fallen into the driver's lap might lead to panic-like reactions. Cigarette stubs thrown out of a window pose a serious fire threat. Some serious traffic accidents in Germany are known to have been caused by a lit cigarette. Some German tribunals have commented on the imprudence of smoking while driving. Smoking may be compared to using a cell phone while driving, which is also banned in some jurisdictions.

More recently, the dangers of secondhand smoke have seen more attention, and smoking in a car (whether in motion or not) is banned in some jurisdictions as a measure against passive smoking. Some laws stipulate that such a ban applies only when a passenger is under a certain age. A research study showed that after smoking one cigarette in a car, the time required for respirable particles' concentration to return to its initial value, depending on car movement cases, windows positions and ventilation settings, varies between 10 and 60 minutes.

Cigarettes or cigarette litter thrown out of the window of cars moving through a vegetated area (particularly during the hot season) is one of the causes of wildfires or bushfires. A southern France firefighters' department statistic attributes 16% of local bushfires to cigarette litter thrown out of moving vehicles (and 13.8% to cigarette litter from pedestrians).

...
Wikipedia