Periodic speed limits
Normally, speed limits apply 24 hours a day and all year round. In certain situations, local authorities can apply a special speed limit to certain stretches of road for particular periods of time or particular days. Outside these times or days, the usual speed limit at that location is in force.
An example of a periodic speed limit is one used near school grounds. One way to show this special limit is through a standard upright sign with an information plate underneath that shows the periods and days when the speed limit applies.
Electronic periodic
Electronic periodic speed signs
speed sign at school
Another way of showing the speed limit is an electronic speed limit sign which when lit up shows the speed limit in white numbers within a red border against a black background. Outside the special speed limit periods, the sign remains blank. Sometimes the electronic sign can be mounted on a grey backing board with two amber lights, which may flash when the sign is lit up.
The sign School Children Crossing Ahead that includes two amber flashing lamps may appear beside periodic speed limit signs to alert you to the presence of school children.
You must not break the periodic speed limits while they are in force.