UK speed limits — by road type and by what you are driving

Almost everyone can recite 30, 60, 70. Almost nobody can say what the limit is in a Transit on a single carriageway, why a lit road with no signs on it is 30 rather than 60, or what the difference is between a 20 mph zone and a 20 mph limit. The theory test asks the second set of questions. Two variables decide every answer — the road and the vehicle — and once you can read both off, the whole topic collapses into one table and three rules.

You MUST NOT exceed the maximum speed limits for the road and for your vehicle (see the table below). A speed limit of 30 mph (48 km/h), or 20mph (32km/h) in Wales, generally applies to all roads with street lights (excluding motorways) unless signs show otherwise.

Note the phrase “for the road and for your vehicle”. Two conditions, and both have to be satisfied. The national limit on a single carriageway is 60 mph — but it is 60 mph for a car. Drive the same road in a van and the maximum you are allowed is 50.

The national speed limit table

These are the national limits. They apply unless a sign says otherwise, and a sign always wins. In the built-up column the first figure is England, Scotland and Northern Ireland; the second is Wales.

Every other column is the same across Great Britain except the bottom row: goods vehicles over 7.5 tonnes are held 10 mph lower in Scotland on single and dual carriageways than in England and Wales.

Three patterns are worth memorising rather than re-deriving:

• Only cars, their close relatives and motorhomes up to 3.05 tonnes get 60 on a single carriageway. Everything else in the table is 50, and heavy goods vehicles in Scotland are 40.
• Towing costs you 10 mph everywhere except in town. 60 becomes 50, 70 becomes 60, on the dual carriageway and the motorway alike.
• Motorway and dual carriageway are not interchangeable. For a car they are both 70, which is why people assume they always match. For a van, a large motorhome or a coach up to 12 metres they differ, and that is where the question is set.

The row that catches most drivers: vans

This is the single most reliable place to lose a mark, and it is also the reason the speed camera van on the dual carriageway is not making a mistake.

Most vans: have a lower speed limit than cars; must follow the speed limits for goods vehicles of the same weight.

A van is a goods vehicle. On a single carriageway that means 50, not 60; on a dual carriageway 60, not 70. Two narrow exceptions carry car limits instead, and both are defined by construction and weight rather than by looks.

The Department for Transport is blunt about how rare the first category is: very few vans meet it, and the ones that do look like a Fiesta van or a Corsa van rather than a panel van. Everything else — including small vans — takes the goods-vehicle limits of 50, 60 and 70. If you think your van is misregistered, the lower limits apply until it is actually re-registered.

What makes a road a 30

The Code says 30 “generally applies to all roads with street lights”. That is not a rule of thumb — it is a legal definition, and knowing it answers the “there were no signs, how was I meant to know?” argument permanently.

a road is a restricted road for the purposes of section 81 of this Act if— (a) in England and Wales, there is provided on it a system of street lighting furnished by means of lamps placed not more than 200 yards apart

Section 81 then sets the number: it is not lawful to drive on a restricted road at more than 30 mph — reduced to 20 mph in Wales by the Restricted Roads (20 mph Speed Limit) (Wales) Order 2022, which came into force on 17 September 2023 and is cited in Rule 124’s own Law line. In Scotland the lighting test is 185 metres and the road must also be of a classification specified in regulations.

So the derivation runs: lamps, therefore restricted road, therefore 30. No sign required, and none is coming.

Why the absence of a repeater sign is itself information

Repeater signs are the small roundels part-way along a road, and their placement is regulated rather than optional.

Schedule 10, Part 4, General Direction 2 of TSRGD 2016 defines the requirements for the placing of speed-limit repeater signs. This states that speed-limit repeater signs must not be placed along a road that is subject to a maximum speed limit of 30mph and has a system of carriageway lighting.

That produces a rule you can use from the driving seat. A 30 is the one limit whose repeaters are forbidden on a lit road — so a repeater roundel you can see on a lit road is telling you the limit is not 30, and a lit road with no repeaters at all is telling you it is. The circular adds that the Department will not make exceptions, and that it should be assumed a 30 applies where there are three or more lamps throwing light on the carriageway, placed not more than 200 yards apart, unless an order has been made and the road is signed to the contrary.

Wales changes the number the reasoning lands on, not the reasoning. Since 20 mph became the default on restricted roads there, those roads carry no repeaters either — so a lit Welsh street with nothing on the lamp posts is a 20, and the roads held back at 30 are the ones the highway authority has signed as exceptions.

The Act closes the loop from the other direction. Where a road has no street lighting, you cannot be convicted of exceeding a posted limit unless that limit is indicated by traffic signs — and where the road is lit, the absence of signs saying otherwise is itself evidence that it is a restricted road.

evidence of the absence of traffic signs displayed in pursuance of this section to indicate that the road is not a restricted road for the purposes of that section shall be evidence that the road is a restricted road for those purposes

Unlit and unsigned, the national limit applies instead — 60 for a car on a single carriageway. That is the honest answer to the country lane with no signs at all, and it is also why Rule 125 exists.

Dual carriageway or motorway?

The Highway Code definition is one sentence long, and it says nothing about lane count, speed, or the colour of the signs.

A dual carriageway is a road which has a central reservation to separate the carriageways.

A central reservation, and that is the whole test. Not hatched paint — a reservation. A two-lane road with a physical divider is a dual carriageway. A four-lane road with only a painted centre is a single carriageway, and single-carriageway limits apply to it however wide it feels.

Being a dual carriageway does not make a road a motorway, and the two are told apart by signs rather than by build:

• Motorway direction signs have blue backgrounds. On other roads, route numbers on a blue background show the direction to a motorway, and blue panels on a green primary-route sign mean the motorway starts at the junction ahead.
• Primary route direction signs have green backgrounds. Non-primary and local routes have black borders, and a route number on a green background there points you to a primary route rather than a motorway.
• Motorways carry restrictions no dual carriageway does. Pedestrians, cyclists, horse riders, learner motorcyclists, motorcycles under 50 cc and certain slow or oversized vehicles MUST NOT use them, and a provisional car licence holder may only drive on one accompanied by a DVSA Approved Driving Instructor in a dual-controlled car showing red L plates, or D plates in Wales.

A learner driving alone is the tell — a provisional car licence holder with nobody beside them cannot lawfully be on a motorway at all, and a learner motorcyclist never can be. Our guide to motorway lane discipline works through what else changes when the road actually is one.

Signs beat the national limit

Signs with red circles are mostly prohibitive. Plates below signs qualify their message.

Four kinds of speed sign live among the signs giving orders, and the exam separates them:

• Maximum speed — a number in a red circle. The legal maximum for that stretch, and it can be set below or above the default the road would otherwise carry.
• National speed limit applies — the white circle with a single black diagonal. It does not mean 60, and it does not mean 70. It means “read the table above” — so the same sign is 60 for a car and 50 for a van on the same road.
• Entry to a 20 mph zone and end of a 20 mph zone — a pair, and different from a plain 20 sign. More on that below.
• Minimum speed and end of minimum speed — not red circles, and easy to misread as a limit. A minimum-speed sign sets a floor, not a ceiling.

On motorways and some dual carriageways the number can change electronically, and Rule 261 makes the displayed figure mandatory.

You MUST NOT exceed a speed limit displayed within a red circle on a sign

The same rule adds the maximum speed limit for the road and for your vehicle as a second MUST NOT, and notes that speed limits are enforced by the police. So a variable limit inside a red circle is enforceable exactly like a painted 40 on a post — the widely repeated claim that gantry limits are “only advisory” ignores the red ring the rule is actually written about.

The blank gantry

A blank signal is not the same as a red X, and it is not the same as a national-limit sign.

• Over a running lane, amber flashing lights warn of a hazard: reduce your speed, and only increase it again once you pass a signal that is not flashing, or a sign displaying a national speed limit or the word END, and you are sure it is safe.
• Over the hard shoulder, blank means closed. A red X or a blank sign above the hard shoulder means you MUST NOT use it except in an emergency; you may only use it as a running lane when a speed limit is shown above it.

So blank over your lane returns you to the national limit for the road once you have passed it; blank over the hard shoulder shuts the hard shoulder.

20 mph zone vs 20 mph limit

They are signed differently because they are built differently, and the difference is a favourite of question writers.

Both are 20 mph and both are enforceable. Inside a zone, Rule 153 adds an instruction that is regularly missed: when you approach traffic-calming features, reduce your speed, allow cyclists and motorcyclists room to pass through them, and maintain a reduced speed along the whole of the stretch of road within the calming measures — not just at each hump. You should not overtake other moving road users while in those areas.

Rule 152 covers the same streets without the engineering: drive slowly and carefully where there are likely to be pedestrians, cyclists and parked cars, and watch for vehicles emerging, doors opening and children running out from between parked cars.

Can you exceed the limit to complete an overtake?

No, and there is no version of the question where the answer changes. The offence has no exception for overtaking, for keeping up with traffic, or for spending less time on the wrong side of the road.

A person who drives a motor vehicle on a road at a speed exceeding a limit imposed by or under any enactment to which this section applies shall be guilty of an offence.

Rule 163 opens with the same standard from the other end — overtake only when it is safe and legal to do so — and the practical consequence is a decision, not a compromise: if you cannot complete the overtake inside the limit, you do not start it. Rule 164 says the same thing about large vehicles in more words: make sure you have enough room to complete the manoeuvre before committing yourself, and if in doubt, do not overtake.

The exemptions that do exist are narrow and are not available to you. Speed limits do not apply to a vehicle being used for fire and rescue, ambulance or police purposes where observing the limit would be likely to hinder that use — a statutory exemption written for the emergency services, not a general defence.

The mirror-image error is worth naming too. Rule 125 is the reason “I was under the limit” is not automatically a defence.

The speed limit is the absolute maximum and does not mean it is safe to drive at that speed irrespective of conditions.

Rule 125 tells you to reduce your speed where the road layout or condition presents hazards such as bends, where you are sharing the road with pedestrians, cyclists, horse riders or motorcyclists, where the weather makes it safer, and at night. Doing 55 in a 60 on a blind country bend can still be too fast; the guide to stopping distances has the arithmetic behind that.

What it costs

The minimum penalty for speeding is a £100 fine and 3 penalty points. Court fines are means-tested — usually a percentage of weekly income, up to £1,000, or £2,500 if you were on a motorway — and disqualification is available. A speed awareness course may be offered if the police decide it is appropriate and you have not been on one in the past three years.

Two extras matter more to recent passers than the fine. Twelve or more points in three years puts you in front of a court for disqualification. And within two years of your first pass, six points revokes your licence outright — a single speeding conviction is half of that allowance. Our guide to the New Drivers Act sets out what revocation actually means and what you have to retake.

Common test questions and the answers

“You are on a dual carriageway in a van. What is the maximum speed limit?”

60 mph. A van is a goods vehicle, and goods vehicles not exceeding 7.5 tonnes maximum laden weight are limited to 60 on a dual carriageway — not the 70 a car gets. Only a car-derived van or a dual-purpose vehicle carries car limits.

“There are street lights but no speed limit signs. What is the limit?”

30 mph — 20 mph in Wales. Street lighting placed not more than 200 yards apart makes the road a restricted road, and a 30 mph limit applies unless signs show otherwise. Motorways are excluded from the rule.

“What does a white circular sign with a black diagonal line mean?”

That the national speed limit applies. It is not a number: it directs you to the national limit for that road and for your vehicle, which is why the same sign means 60 to a car driver and 50 to a van driver on a single carriageway.

“You are towing a caravan on a motorway. What is your maximum speed?”

60 mph. Towing drops both the dual carriageway and the motorway figure from 70 to 60, and the single carriageway figure from 60 to 50. On a motorway with three or more lanes, Rule 265 also closes the right-hand lane to any vehicle drawing a trailer.

“You are overtaking on a single carriageway and would need 65 mph to finish safely. What should you do?”

Do not overtake. Exceeding the limit is an offence with no overtaking exception, and Rule 163 requires an overtake to be legal as well as safe. If it cannot be completed inside the limit, it is not an overtake you should have started.

“What is the difference between a 20 mph zone and a 20 mph limit?”

A zone is built with traffic calming and is signed inside with repeaters or roundels at close intervals, with terminal signs at each end; it usually covers several roads. A limit is signed only, with terminal and repeater signs, and needs no calming features. Both carry the same 20 mph maximum.

“A gantry sign over your lane goes blank. What does it mean?”

Over a running lane, it returns you to the national speed limit for that road once you have passed it and are sure it is safe — the same effect as a signal that has stopped flashing or a sign showing END. Over the hard shoulder, a blank sign means the opposite: you MUST NOT use it except in an emergency.

Where this shows up in revision

Speed limits run through the Rules of the road, Motorway rules, Road and traffic signs and Vehicle loading topics — the towing rows are examined from the loading side as often as the speed side. Read Rules 124, 125, 136 to 138, 152, 153, 163 to 166, 253, 257, 261 and 269 in the Highway Code, learn the circular signs on road signs, check the abbreviations in the glossary, work the 14 DVSA topics, and sit a full mock theory test under the real timer. It is free to get started.

For the wider question of which parts of the Code are enforceable at all, our guide to MUST vs should explains how Rule 124 and Rule 125 do different jobs — and lesser-known driving offences covers the habits that carry a penalty most drivers do not expect.

Sources

• GOV.UK — Speed limits — the national speed limit tables by vehicle type, vans, motorhomes, speed limiters
• GOV.UK — Highway Code: general rules, techniques and advice for all drivers and riders (Rules 124, 125, 136–138, 152, 153)
• GOV.UK — Highway Code: using the road (Rules 162–166, overtaking)
• GOV.UK — Highway Code: motorways (Rules 253, 257, 261, 265, 269)
• GOV.UK — Highway Code: traffic signs — signs giving orders and direction sign colours
• DfT — Car-derived vans and dual purpose vehicles
• DfT — Setting local speed limits — repeater signs, street lighting, 20 mph zones and limits (applies to England)
• legislation.gov.uk — Road Traffic Regulation Act 1984, section 81 (general speed limit for restricted roads)
• legislation.gov.uk — Road Traffic Regulation Act 1984, section 82 (what roads are restricted roads)
• legislation.gov.uk — Road Traffic Regulation Act 1984, section 85 (traffic signs for indicating speed restrictions)
• legislation.gov.uk — Road Traffic Regulation Act 1984, section 87 (exemption of fire brigade, ambulance and police vehicles)
• legislation.gov.uk — Road Traffic Regulation Act 1984, section 89 (speeding offences generally)
• legislation.gov.uk — The Restricted Roads (20 mph Speed Limit) (Wales) Order 2022
• Welsh Government — Introducing default 20mph speed limits
• GOV.UK — Speeding penalties
• GOV.UK — Theory test: revision and practice

Highway Code, GOV.UK and DfT excerpts are reproduced under the Open Government Licence v3.0.