How does
.competence of drivers
.substance abuse
.pedestrians
.cyclists
.livestock
be responsible for road accidents?

The competence of the drivers can be responsible for road accidents because a less competent driver is more likely to commit mistakes in the road ending to accidents while a more competent driver is more likely to be very cautious in driving.
The substance abuse too can be responsible for road accidents because people who are driving and is currently on substance abuse will like to wrongly judge the situations on the road that may cause an accident.
The pedestrians can be a factor in road accidents because of the stubborness of people like neglecting traffic lights resulting to accidents.
Cyclists can also create a chaotic and crowded aura on the roads and this can affect some other drivers that may cause and accident on the road.
In rural areas, domestic animals are really tame that they actually roam around everywher including roads.