When should you use your turn signals on a commercial vehicle?

Signal any time you change direction: turning, changing lanes, pulling away from the curb, or pulling onto a highway from the shoulder. Signal well before the turn so other drivers have time to react — at highway speed this means at least three to five seconds before you begin the maneuver. Cancel the signal after the turn because a forgotten signal misleads other drivers into thinking you are about to turn when you are not. Brief or last-second signals provide no warning and are nearly as bad as no signal at all. Always signaling regardless of whether other vehicles are visible builds the habit so you never forget when it matters; you may not see every vehicle around you, especially in blind spots.