Intentional wrong-way driving
A distinction should be made between intentional and unintentional wrong-way driving. Intentional wrong-way driving is done, for example, from ‘acting hard’, ‘recklessness’ or ‘overconfidence’, whether or not motivated by alcohol or drugs, or as a suicide attempt. This is more often the case among the younger wrong-way drivers  .
Unintentional wrong-way driving
Unintentional wrong-way driving is often the caused by orientation problems. For example, drivers do not notice that they enter the exit of a motorway approach instead of the access, or they think that they are turning off onto a ‘normal’ road and do not notice at all by that are entering a motorway. The specific design of accesses and exits plays an important role . This form of unintentional wrong-way driving occurs mainly among the elderly wrong-way drivers  . Alcohol and drugs can also be the cause of unintentional wrong-way driving. Finley et al.  for example, found that drivers under the influence of alcohol have different search and viewing patterns when entering a motorway and are less capable of observing certain colour contrasts on traffic signs well than sober drivers.
Influence of alcohol and drugs
The use of alcohol, drugs or medication is a factor in many of the wrong-way driving crashes. However, no data is known for the Netherlands. Estimates from the United States range from around 50% to over 60%   and Doctor  even mentions a percentage of 70%. Gerlach & Seipel  on the other hand, report that alcohol played a role in 14% of the German wrong-way driving crashes; drugs and medications are not mentioned. Based on Swiss data, Scaramuzza & Cavegn  have calculated that the risk of a wrong-way driving crash is more than 3.5 times greater if alcohol, drugs or medication are involved.