Understanding Speed Limits

The UK is well known for having one of the best and most admired road safety records in the world. This could be partly due to the speed restrictions that we impose on the road network throughout the country with the intention of encouraging safer and more responsible driving.

A History of Speed Limits

Britain's Speed Limits have come a long way since 1865 when the Locomotive Act restricted the speed of horse-less vehicles to 4mph in open country and 2mph in towns. The act required 3 drivers for each vehicle - 2 to travel in the vehicle and 1 to walk ahead of it carrying a red flag. Hence the Red Flag Act was born.

Speed restrictions as we know them today came into force over 60 years ago in 1934 when a 30mph limit was brought in for roads considered to be in 'built-up' areas. This particular limit is still used today.

Other roads had no limits, until 1965 when the Minister for Transport introduced a 70mph restriction for all roads, which included highways and motorways.

In 1977 the speed limit for cars and motorbikes on dual carriageways was set at 70mph with single carriageways carrying a 60mph limit.

The limits remained untouched apart from a few exceptions, until 1999 when local authorities were allowed to bring in 20mph speed limits without needing to get permission from the Secretary of State.

So Who Sets the Speed Limits in the UK?

The Highways Agency sets speed limits on motorways and the trunk road network. The Government also offers advice to traffic authorities on which speed limits to set in their individual areas. They take into consideration local circumstances and issues and based on their findings, decide on an appropriate limit for their roads, which can be between 20-70mph inclusively.

The Different Speed Limits and Where to Find Them

20mph Speed Limit

Introduced in 1999 and set by local councils, the 20mph limits are mostly used in urban areas, such as residential roads (particularly narrow ones), town centres and around schools and nurseries. The reasons are obvious - where there is a high concentration of pedestrians, it makes sense to keep the limits slower to avoid collisions and accidents. Usually the 20mph will come under a 'zone' which will combine other traffic calming measures like speed humps with the lower limits.

30mph Speed Limit

Also seen in urban areas and villages since its introduction in 1934, there will only be a sign at the beginning of a 30mph zone. This is because roads under this limit are easily identifiable by a system of streetlights. This in itself confuses people despite being rather simple - here's what you need to remember: the 30mph speed limit applies to all traffic on all roads with street lighting unless road signs show that a different speed limit applies. If the road is unlit then there will be repeated 30mph signs along or beside the road for the duration of the limit area.

40mph and 50mph

Introduced to be used in non-built up areas where a higher speed is considered to be safe and appropriate. The beginning of the speed limit must be clearly signed and repeater signs must be placed at regular intervals along the length of road that the limit pertains to.

National Speed Limit

When you enter an area that is signed by a diagonal black stripe on a white background, you are driving under national speed limit restrictions. For most vehicles this will means 60mph on single carriageway roads and 70mph on dual carriageway roads. It is also 70mph on the motorway network unless otherwise indicated.

Temporary Restrictions

Temporary speed restrictions are often put in place to encourage safer driving during road repairs with the intention of making the area safe for those working there. When on Motorways and faster roads they are usually enforced by very visible warning signs and speed cameras.

Speed Limits, Not Targets.

It's important to remember that a speed limit is just that - the top speed that you can drive at on any particular road. It's not a target speed, and just because you are allowed to drive at a particular speed, doesn't mean that it's always going to be safe to do so. For example: 70mph may be fine on a sunny day, but dangerous on an icy, snowy winter morning.

Many factors other than speed come into safe driving, so remember that working out your 'safe speed' will be a continuous assessment for the duration of your drive. With this in mind, take care to ensure that you adjust your speed in accordance with the road conditions and stay always stay within the limits.