What should you do?
Slow down and prepare for the hazard described, such as road works, lane closures or diversions.
How to recognise it
A portable trailer with a black electronic panel showing amber text such as ROAD WORKS, set behind traffic cones.
Common confusion
Mobile message signs are temporary; their messages override what you expect from normal fixed signs on that road.
Explanation written by the My Driving Test editorial team using the Department of Transport Traffic Signs Manual conventions and the RSA Rules of the Road.
