S960_lane Closure Ahead Photo 960

Some signs are designed to provide information about varying traffic conditions, such as delays or diversions ahead, or to warn of specific hazards, such as animals or debris in the road. These are called ‘variable message signs’ and may be free-standing with an electronic display, such as the signs that have been erected above motorway hard shoulders. Some direction signs contain variable elements. They might show, for example, alternative routes, or the availability of spaces in car parks. Signs activated by moving vehicles are provided as a road safety measure. They can give a reminder of the speed limit, or warning of a hazard such as a bend or crossroads. They are activated when a vehicle is travelling above a certain speed and the driver needs to slow down.