Accidents involving 3 or more vehicles can also occur when a driver has his car rear-ended. This type of accident is often referred to as a "chain link" type of accident. These accidents typically occur because the second vehicle in line stops short as a result of striking the vehicle ahead of it, resulting in a chain reaction where each succeeding vehicle in line strikes the vehicle ahead of it. One should be cognizant of the fact that merely because car #2 stopped short as a result of striking car #1, does not necessarily absolve car #3 of liability for striking car #2 in the rear. Car #3 may still be liable because, generally speaking, driving with reasonable care requires each vehicle to drive a sufficient distance behind the vehicle in front of it so that if the vehicle ahead of you stops short for any reason, the trailing vehicle should still be able to stop in time without striking another vehicle in the rear. Loosely stated, if a vehicle rear-ends another vehicle that was traveling directly in front of it, then the vehicle either was following too closely (also known as tailgating), or failed to be attentive enough and react as a reasonably prudent (non-negligent) driver would have reacted under the circumstances. A safe driving distance is generally thought to consist of at least 1 car length for every 10 miles per hour that one is traveling. Therefore, if you and the driver ahead of you are driving on a highway at 60 MPH, you should be sure to leave at least 6 car lengths between the front of your vehicle and the rear of that vehicle. This safe driving distance is not set in stone but it is a formula often cited by engineers and accident reconstruction experts while testifying in court during jury trials. The distance takes into account human factors like normal reaction times and actually may include discussion or analysis of the relationship between brain recognition and the time it takes for the body to physically react. Of course, even what is considered a safe driving distance is only going to be sufficient to prevent an accident involving an attentive driver. A second lost glancing at a cell phone, radio or car passenger can and will change the equation completely.