If the average speed on a road increases, crash risk also increases, as does the risk of a serious outcome. This is true in general terms, but more so when motorised vehicles crash with unprotected road users, such as pedestrians, cyclists and (light) moped riders. Furthermore, speed differences between vehicles at any one time or place are related to a higher crash risk.

Risky road user behaviour is behaviour that adversely affects road safety, such as driving under the influence of alcohol, drugs or medicines, speeding, inappropriate speed, distracted or fatigued driving, red light negation, and failure to use or misuse means of protection (motorcycle or moped helmet, seatbelt).

The mobile phone is symbolic of ‘distraction in traffic’. But apart from mobile phone calls, texting, or listening to music, many drivers, cyclists and pedestrians are occupied with all sorts of other activities that may distract them. Examples are: operating the navigation system, eating, drinking, talking to passengers or daydreaming.

From 2009 to 2018, an annual average of 80 road deaths were attributable to crashes with trucks and 67 road deaths to crashes with delivery vans. Casualty numbers are higher among crash opponents than among occupants of trucks or delivery vans. The fatality rate among crash opponents is higher when they crash into a truck or delivery van than when they crash into a car.

Driving under the influence of drugs or impairing medicines reduces fitness to drive[i] and increases crash risk. Drugs have a numbing, stimulating or mind-altering effect on the brain, or a combination of these effects, which impair traffic task performance.

Driver fatigue is estimated to be a (contributing) factor in 15 to 20% of crashes, but estimates in individual studies vary widely. Drivers who are tired are less attentive and react less quickly and less adequately than drivers who are not tired. They also get irritated and frustrated more easily.

In the past ten years (2006-2015) an average of 11 road deaths per year in the Netherlands was registered in crashes involving agricultural vehicles. Compared to the early 1990s, the average number of road deaths due to crashes involving an agricultural vehicle increased from 1% to 2% of the total number of road deaths in the Netherlands.