One situation where you shouldn't back up is when you overrun a “stop line” at an intersection while stopping for a red light (or stop sign). If this happens, and you find yourself straddling the crosswalk, it is usually better to stay where you are, rather than backing up to the proper place.

Legally and for safety, you should never back up at a stop light unless it is absolutely necessary to avoid an immediate hazard or directed by a police officer. In most jurisdictions, including under the 2026 "Rules of the Road" regulations, reversing into an intersection or against the flow of traffic is considered "unsafe backing" and can result in a significant fine or a "reckless driving" citation. If you have accidentally pulled too far forward and are blocking a pedestrian crosswalk or find yourself under a red light, it is generally safer to remain stationary or cautiously proceed if the way is clear (and legal), rather than reversing into the vehicle behind you. Reversing at a light is extremely dangerous because the driver behind you is not expecting you to move backward; most "fender benders" at intersections occur because a driver panics and reverses without checking their rearview mirror. If you missed your turn, the grounded and correct procedure is to continue through the intersection and find a safe, legal spot to make a U-turn or circle back. Your safety and the safety of the cars behind you always outweigh the convenience of a quick correction.