Drivers who enter cycle boxes at traffic lights are being warned they could receive a fine and penalty points on their licence.
Cycle boxes, officially known as Advanced Stop Lines (ASL), allow cyclists to move to the front of traffic at junctions.
Motorists entering ASLs could face three penalty points on their driving licence and a £100 fixed penalty fine if they move into a box when the lights are red.
If lights change from green to amber and the driver cannot safely stop, they can cross the first line but must stop before the second stop line.
Rule 178 of the Highway Code states: “Motorists, including motorcyclists, must stop at the first white line reached if the lights are amber or red and should avoid blocking the way or encroaching on the marked area at other times, e.g. if the junction ahead is blocked.
"If your vehicle has proceeded over the first white line at the time that the signal goes red, you must stop at the second white line, even if your vehicle is in the marked area.”