According to Federal studies, cars with amber turn signals are around 28% more effective at avoiding crashes than cars with red lights, in cases where the turn signal can be an issue. Overall, cars with amber turn signals are 5.3% less likely to be hit from behind than cars with red turn signals. (In contrast, third brake lights — a considerably more expensive solution — were mandated in 1986, based on an estimated 4.3% crash avoidance rate). Lighting expert Daniel Stern tells about the issues in this week’s new feature on preventing crashes by using amber turn signals – which the U.S. government’s own research indicates are considerably more effective than third brake lights — and provides some information on converting to amber signals.