The single most common cause of motor vehicle collisions is improper driving.?

This is incorrect. According to the National Highway Traffic Safety Administration (NHTSA), the most common cause of motor vehicle collisions is driver distraction. Driving while distracted is any activity that takes a driver's attention away from driving, such as talking on a cell phone, texting, eating, or adjusting the radio. It can also include distractions outside the vehicle, such as looking at billboards or other scenery. Distracted driving can slow a driver's reaction time, impair their judgment, and increase the risk of a collision.