Speed limits are usually indicated by a circular sign with a red outer ring and number on top of a white background. You must always obey the speed limit and in the appropriate conditions you can drive up the maximum limit. However, as the name suggests, it is a limit and not a target and the speed you drive on any given road should be determined by a range of factors, such as: the weather conditions you are driving in; the presence of cyclists or pedestrians on the road, and; the type of road you are driving on, to name a few.
Adjust your speed
The presence of other road users such as horse riders, pedestrians or cyclists is likely to mean you will need to slow down and drive well below the speed limit until it is safe for you to pass them. When you see one of these fellow road users it is a good idea to slow down as you approach so you don’t have to abruptly stop behind them and have a clear view past them. Always make sure to give cyclists, pedestrians, and horses plenty of room as you pass them.
If you are driving behind another vehicle then you should also adjust your speed accordingly so that you are not driving too close to their rear bumper. The situation may arise where they need to stop suddenly due to something you cannot see or predict so you need to be far enough behind to stop without getting too close to their car or worse crashing into it. This means you will have to drive below the speed limit if they are and also maintain a safe distance behind even if they are driving slowly.
You also need to be aware that some vehicles have different speed limits on particular roads. This means you need to know the class of the vehicle you are driving and the speed limit for that class on certain roads.
Minimum speed requirements
In some cases, there may be signs indicating that you are required to go at a minimum speed. Minimum speed requirement signs are indicated by a blue circular sign and a white number indicating the minimum speed. When you see this sign, you must not drive any slower than the minimum speed. The minimum speed zone will be demonstrated by the same sign with a line through it.
National speed limit
The national speed limit applies when there are no signs to tell you what the speed limit is AND when you are not in a built-up area. Sometimes there are signs on the road to tell that the national speed limit applies to the road you are on (see picture below). However, just because the national speed limit applies, this does not mean you need to try and go at that speed and the speed limit would not be suitable on many country lanes where the national speed limit often applies.