Driving instructor’s 30-second trick to know speed limit

Francis Noakes shared the advice on his YouTube channel, Driving School TV, explaining that drivers can use sign size and street lighting as key indicators, particularly in urban areas.

He encourages motorists to look out for whether or not the road contains bigger or smaller speed limit signs.

Driving instructor’s trick for knowing speed limit on UK roads

The driving instructor explains that the speed limit in England and Scotland is generally 30mph in built-up urban areas where there is street lighting.

UK speed limits explained

However, local councils can vary the speed limit if they want to.

He says a big speed limit sign signals a change in speed limit, while smaller ‘repeater’ signs are used to remind drivers of the speed limit when travelling through an urban area where the speed limit differs from 30mph.

Mr Noakes said: “In the UK, if we’re in a built-up urban area and there’s street lighting, the speed limit is 30, but councils can vary that speed limit if they want to.

“If the speed limit is 40mph, there’s speed limit repeaters all the way down the road because it’s not the urban speed limit.

“Same with this road, the speed limit is 20mph so there’s repeaters all the way down the road.

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“There’s no hard and fast rule of how often they should be repeated, but you will find repeaters.

“Some good advice that I say is wait 30 seconds to a minute, if you haven’t seen a repeater sign then your speed limit is 30mph.

“Why? Because if it’s not 30 mph then they will not repeat the sign, it’s the urban speed limit.”

The Highway Code supports this, with Rule 124 stating: “The presence of street lights generally means that there is a 30 mph (48 km/h) speed limit unless otherwise specified.”

Government guidance also confirms that this applies to all single and dual carriageways with street lighting in England, Scotland, and Northern Ireland, unless signs indicate otherwise.

However, in Wales, the default speed limit on lit roads has been reduced to 20mph unless otherwise signed.

Mr Noakes also clarified the difference between large and small speed limit signs.

He said: “If you’ve been going at 30mph down this road [which is a 20mph speed limit] and then slow down once you spot the repeater sign, then you’ve already been caught speeding.

“The big signs signal a change in speed limit.

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“The little ones are just a repeater sign, reminding you of the speed limit.”

The government says repeater signs for a 30mph speed limit are used only on roads with no street lighting.

Repeater signs for the national speed limit (60 mph) are used only on roads with street lighting.

The minimum penalty for speeding is a £100 fine and three penalty points on your licence.

Have you noticed the bigger and smaller speed limit signs in your local area? Let us know in the comments below.