The next time you’re on a smart motorway and the gantry is blank, don’t think that the cameras are turned off. Even when display screens are inactive and completely black, the integrated speed cameras are still active and can capture the number plates of speeding drivers. Likewise, speed limits on smart motorways are not advisory despite drivers mistakenly thinking this to be the case. The speed displayed in a red circle on the electronic boards is mandatory and you must to stick to it. If the speed limit is accompanied by orange flashing lights, then the limit is advisory.