Youth
Insurance statistics demonstrate a notably higher incidence of collisions and fatalities among drivers aged in their teens or early twenties, with insurance rates reflecting this data. These drivers have the highest incidence of both collisions and fatalities among all driver age groups, a fact that was observed well before the advent of mobile phones.Females in this age group exhibit somewhat lower collision and fatality rates than males but still register well above the median for drivers of all ages. Also within this group, the highest collision incidence rate occurs within the first year of licensed driving. For this reason, many US states have enacted a zero-tolerance policy wherein receiving a moving violation within the first six months to one year of obtaining a license results in automatic license suspension. South Dakota is the only state that allows fourteen year-olds to obtain drivers licenses. Old age
Old age, with some jurisdictions requiring driver retesting for reaction speed and eyesight after a certain age. Sleep deprivationVarious factors such as fatigue or sleep deprivation might increase the risk, or numbers of hours driving might increase the risk of an incident. 41% of drivers self report having fallen asleep at the wheel. : 41  It is estimated that 15% of fatal crashes involve drowsiness (10% of day time crashes, and 24% of night time crashes). Work factors can increase the risk of drowsy driving such as long or irregular hours or driving at night. Drug use
Including some prescription drugs, over the counter drugs (notably antihistamines, opioids and muscarinic antagonists), and illegal drugs.
In Europe, there are now EuroRAP tests that indicate how "self-explaining" and forgiving a particular road and its roadside would be in the event of a major incident. In the UK, research has shown that investment in a safe road infrastructure program could yield a 1⁄3 reduction in road deaths, saving as much as £6 billion per year. A consortium of 13 major road safety stakeholders have formed the Campaign for Safe Road Design, which is calling on the UK Government to make safe road design a national transport priority. Vehicle design and maintenance
Seat beltsResearch has shown that, across all collision types, it is less likely that seat belts were worn in collisions involving death or serious injury, rather than light injury; wearing a seat belt reduces the risk of death by about 45 percent. Seat belt use is controversial, with notable critics such as Professor John Adams suggesting that their use may lead to a net increase in road casualties due to a phenomenon known as risk compensation. However, actual observation of driver behaviors before and after seat belt laws does not support the risk compensation hypothesis. Several important driving behaviors were observed on the road before and after the belt use law was enforced in Newfoundland, and in Nova Scotia during the same period without a law. Belt use increased from 16 percent to 77 percent in Newfoundland and remained virtually unchanged in Nova Scotia.