In Belgium, almost one in five injury accidents is a unilateral accident, a traffic accident involving only one road user – a motorist or cyclist. Moreover, these accidents are extremely fatal.  According to the Traffic Safety Institute Vias’ latest report, one-sided accidents cause 37% of road deaths.

In other words, more than one in three of all road deaths in our country occur in single-vehicle accidents. One-sided accidents involving motorists account for just over half (53%).

It is, therefore, vital to learn more about these types of accidents. According to Vias’ analysis, more one-sided accidents occur in areas with less traffic. This is not surprising: densely populated municipalities are characterized by many different types of road users, resulting in more frequent accidents between motorists and other road users.

Most unilateral accidents happen at night: between 1 a.m. and 4 a.m., approximately one in two accidents is one-sided. Most single-vehicle accidents happen on Tuesday night, around 3 o’clock in the morning: 62%.

Alcohol, human factors, and environmental factors

Factors that can play a role in single-vehicle crashes are driving under the influence of alcohol or drugs, other human factors, and environmental factors. Cyclists and motorcyclists are approximately three times more likely to be under the influence in single-vehicle crashes than in the total number of crashes involving cyclists and motorcyclists. This is 3.5 times more common among motorists in single-vehicle crashes and even 5 times more among truck drivers.

Most registered human factors are crashes and loss of vehicle control in an accident involving a car (92% of human factors) or a truck (93%). The most registered environmental factors are poor condition of the road or cycle paths (in case of an accident with a bicycle) or sharp bends.

Obstacles

Obstacles that are most often collided with by motorists in a single-vehicle accident are (lighting) poles (26%), trees (22%), and crash barriers (17%). Cyclists most often collide with posts (43%), median strips (15%), trees (11%), and fencing (11%).

The consequences of single-vehicle accidents depend on the type of road user. For example, cyclists who die in single-vehicle crashes make up only 18% of all cyclists who die in road crashes. For car occupants, single-vehicle crashes account for ‘only’ 22% of victims but 53% of fatalities.