The rear driver is often liable for a rear end collision, but not necessarily. When an accident is the result of following too closely or tailgating, the rear driver is likely to be at fault. But there can be other factors that affect who is liable. For example, if one driver is tailgating and the other driver checks their brakes and causes a collision, the driver who hit their brakes may be liable for the collision – and may also face criminal charges for reckless driving. Consult with your Arizona car accident lawyer regarding your situation.