How far in advance of a turn or lane change should you signal?

Most states require you to signal at least 100 feet before a turn or lane change in a residential or city area, and longer (sometimes 200 feet) on highways. The point of signaling early is to give other drivers, cyclists, and pedestrians time to react — to slow, to clear the lane you are moving into, or to anticipate your maneuver. A last-second signal provides almost no warning. Signaling 'just in case' someone is in a blind spot is a habit that keeps you safe even when you cannot see other traffic. After completing the turn or lane change, cancel the signal so it does not mislead other drivers. Even on empty roads, the habit of signaling correctly is what keeps you doing it right when it matters.