Which of the following is a common cause of car accidents?

Driving under the influence is a leading cause of car accidents due to the impairing effects of alcohol and drugs on a driver's cognitive functions and motor skills. When an individual operates a vehicle while affected by substances, their reaction times slow down, judgment becomes clouded, and the ability to perform essential driving tasks diminishes. This significantly increases the likelihood of collisions, as impaired drivers often fail to react appropriately to traffic signals, pedestrians, and hazardous conditions on the road.

In contrast, the use of turn signals, adhering to speed limits, and maintaining a safe following distance are all positive driving practices that contribute to road safety. These actions promote clear communication between drivers and help prevent misunderstandings or dangerous situations. Thus, they do not contribute to accidents in the same way that driving under the influence does.