The AA has issued a warning for everyone who ignores a common motorway sign - and it's one all drivers must follow.
Although the sign is often ignored, drivers can land themselves with a fine of up to £100 and points on their licence. Ignoring it can also put themselves and other drivers in danger, reported The Mirror.
The sign in question is the red 'X' you can find on an overhead gantry while driving on a smart motorway. If you've ever driven on such a motorway before it is likely you've spotted at least one - in fact, you've probably seen several.
