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.

Children are a vulnerable group among road users. They are, after all, still building up skills which will eventually allow them to become safe and independent road users. The role of parents in teaching their children how to behave safely in traffic is very important.  In this fact sheet, children are taken to belong to the age category 0 to 14, unless specified otherwise.

A bicycle helmet is intended to protect cyclists against head and brain injuries when they are involved in crashes. The helmet does not prevent bicycle crashes (see the SWOV fact sheet Cyclists for general bicycle safety measures).

The elderly have a higher than average fatality rate in traffic. The most important cause of this high fatality rate among the 75 year olds and older is their greater physical vulnerability. In addition, functional limitations can lead to the elderly more frequently being involved in certain types of crashes.