#15: Turn Signal Timing: More Than Just Courtesy
A blinking light only helps other people if they have enough time to see it and respond. Turning it on while the steering wheel is already moving misses much of the point. Many states specify a minimum distance before a turn, with 100 feet being a common requirement in urban driving, although the exact rule is not universal and can change depending on location or road conditions. Earlier signaling gives a cyclist, pedestrian, or driver behind you time to understand whether you are slowing for a turn rather than simply braking for no obvious reason.
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