Chain Collision Prevention (CCP) includes systems, devices, apparatus for preventing chain collisions and chain reaction crashes, in vehicle columns. A vehicle-installed deceleration indicator and immediately relays and sequentially transmits Closing Alert signals using radio or other media, down the chain of closely following vehicles when deceleration occurs. Vehicle operators are alerted by alarms and warnings, Cruise Controls can be automatically turned off, and radios silenced. The Closing Alert signals can include a display of rearwardly facing blue vertical Rear Warning Light(s), that are visible to both CCP equipped and non-equipped vehicles. One light indicates a vehicle is CCP equipped and is moving forward. Two lights can indicate a vehicle deceleration in the chain of vehicles ahead. Three lights can indicate a stopped vehicle, and flashing can be vehicle backing or reversing. Cameras provide images of forward and rearward located vehicles.