In the U.K., street lights mean that there is a 30 m.p.h. limit. (Unless signs say otherwise, and apart from motorways.)

Where you see the national speed limit sign (white circle, black diagonal line), you can go faster. The national speed limit for car drivers is 60 m.p.h. on single lane roads, and 70 m.p.h. on dual carriageways and motorways. If the road has no street lights, it will normally be national speed limit, unless signs say otherwise.

If the speed limit is not what you would expect it to be, there will be repeater speed limit signs. Repeater signs remind you what limit is already in force, and are smaller than normal speed limit signs. For example, you would see these on a road with street lights where a 40 m.p.h. limit is in force.