Vehicles equipped with automatic braking or front-collision warning are less likely to cause a rear-end crash, according to a study released Thursday by the insurance industry. The Insurance Institute for Highway Safety says automatic braking - which can bring the car to a stop if it senses an imminent collision - can reduce rear-end crashes by 40 percent. Front collision warning - which warns the driver but doesn't brake - cuts the risk of a rear-end crash by 23 percent. The institute measured the systems' effectiveness by looking at police records for 7,490 rear-end crashes in 27 states.