Dual Carriageway Speed Limits in the UK
The national speed limit on dual carriageways is 70 mph for cars and motorcycles, but varies significantly for vans, HGVs and vehicles towing trailers.
Speed Limits by Vehicle Type
| Vehicle Type | Speed Limit | Notes |
|---|---|---|
| Cars & motorcycles | 70 mph | National speed limit |
| Vans (up to 3.5 tonnes) | 60 mph | 10 mph lower than cars |
| Towing caravan/trailer | 60 mph | Includes motorhomes towing |
| HGV (over 7.5 tonnes) | 50 mph | 60 mph for rigid body not towing |
| Buses & coaches | 60 mph | Regardless of length |
Understanding Dual Carriageway Speed Limits
A dual carriageway is defined as a road where the two directions of traffic are separated by a central reservation. This physical barrier may be grass, concrete, Armco steel, or wire rope. Dual carriageways are common throughout the UK, ranging from major A-roads like the A1(M) approaches and A14 to shorter bypasses around towns.
For cars and motorcycles, the national speed limit on dual carriageways matches motorways at 70 mph. However, the key difference for commercial vehicles is that HGVs over 7.5 tonnes are permitted to travel at 50 mph on dual carriageways compared to 60 mph on motorways. This lower limit reflects the greater mix of traffic on dual carriageways, which may include roundabouts, right-turning traffic, and junctions at grade level.
Vans -- defined as goods vehicles not exceeding 3.5 tonnes maximum laden weight -- are limited to 60 mph on dual carriageways. This is 10 mph less than the car limit but 10 mph more than the van limit on single carriageways. Many drivers of larger panel vans such as the Ford Transit or Mercedes Sprinter are unaware of this restriction, as there are rarely reminder signs beyond the initial national speed limit sign.
When towing a caravan or trailer, the speed limit drops to 60 mph on dual carriageways. This applies regardless of the towing vehicle type. Exceeding this limit while towing is particularly dangerous due to the risk of caravan instability (snaking) at higher speeds.
Speed enforcement on dual carriageways typically involves a mix of fixed cameras (Gatso and Truvelo), average-speed cameras (SPECS) on longer stretches, and mobile camera vans. Many dual carriageways also have advisory variable message signs that can display lower advisory limits during incidents or adverse weather.
It is important to note that many dual carriageways have locally-imposed lower speed limits, particularly through towns, near junctions, or in areas with a history of collisions. Always observe posted signs, which override the national speed limit. Common lower limits on dual carriageways include 40 mph, 50 mph, and occasionally 30 mph through built-up stretches.
Key Facts
Car Limit
70 mph
Van Limit
60 mph
HGV Limit
50 mph
Frequently Asked Questions
What is the speed limit on a dual carriageway?
The national speed limit on a dual carriageway is 70 mph for cars and motorcycles. Vans and buses are limited to 60 mph, vehicles towing a trailer to 60 mph, and HGVs over 7.5 tonnes to 50 mph (60 mph for rigid-body lorries not towing).
What is the difference between a dual carriageway and a motorway?
A dual carriageway is any road with a central reservation separating opposing traffic, whether or not it has grade-separated junctions. A motorway is specifically designated with an M number and has restrictions (e.g., no learner drivers, no cyclists, no slow vehicles). While the car speed limit is the same (70 mph) on both, HGV limits differ and motorways have specific lane restrictions.
How do I know if I am on a dual carriageway?
A dual carriageway has a physical central reservation (grass, barrier, or concrete) separating the two directions of travel. If the road has a painted centre line but no physical barrier, it is a single carriageway regardless of how many lanes it has.