A National Highway Traffic Safety Administration (NHTSA) study shows 'Center High-Mounted Stop Lamps (CHMSLs), required on cars since 1986, cut police-reported crashes by up to 137,000 and non-fatal injuries by up to 70,000 per year. The lights can cause headaches for car designers but save insurers millions in property damage claims. The NHTSA says the lights reduce property damage costs by almost $500 million a year. Answering critics who said the lights were a waste of money, NHTSA says they save $3.18 in property damage for every dollar they cost. And that doesn't include the injuries they prevent.
SAE/DOT Certified CHMSLs are required on all new trucks in 1994 and have proven equally effective at reducing the number of rear-end crashes in mini-vans, SUVs and pickup trucks, even though many questioned whether trucks - with their higher rear ends - needed the lights at all.
According to the Highway Traffic Safety Administration, those center brake lights on cars really work -- reportedly preventing at least 92,000 crashes, 58,000 injuries and $655 million in property damage each year.
Often mounted on the bottom-center of the back windshield, the third brake light creates a triangle with the two brake lights located above the bumper. The result is a more visible warning for drivers when the vehicle in front of them is coming to a stop. Since 1986, the third light -- which is mounted closer to a driver's eye level -- has been required safety equipment on cars. Sport utilities and pickup trucks have been required to have the third light since 1994.