Why does the risk of a crash increase with the number of passengers in a vehicle?

The risk of a crash increases with the number of passengers in a vehicle primarily because there are more distractions. When additional people are present in the car, they often engage in conversations, share music, or participate in other activities that can divert the driver's attention from the road. This increase in distractions makes it harder for the driver to remain focused, which can compromise their ability to react appropriately to situations such as sudden stops, pedestrians in the roadway, or the actions of other drivers.

It's important to consider the nature of distractions as well. Each passenger has the potential to demand attention and contribute to a chaotic atmosphere, particularly in an environment where drivers need to be alert and attentive. Therefore, the presence of multiple passengers can significantly affect driving performance and increase the likelihood of an accident.