The main differences between motorways and dual carriageways
Despite having some similarities, there are a number of differences between the two types of road.
Some of the differences between dual carriageways and motorways are:
Motorways MUST NOT be used by :
▪ riders of motorcycles under 50 cc, cyclists, horse riders.
▪ certain slow-moving vehicles and those carrying oversized loads (except by special permission).
▪ agricultural vehicles.
▪ powered wheelchairs/powered mobility scooters
Motorways have a hard shoulder while dual carriageways do not
Motorways have the “M” designation before or after the road number, such as M40 or A40(M). The addition of the ‘(M)’ means the former dual carriageway (the A40) has been upgraded to motorway status
Junctions on motorways are always numbered.
The dual carriageway signs are always green, while they are blue on Motorway.
on a dual carriageway, we use the right-hand lane for overtaking and turning right, On a motorway, it is used for overtaking only.
Exiting a motorway almost always involves a slip road
Roundabouts and traffic lights are very common on dual carriageways but extremely rare on motorways.
These are key differences, but there are also some similarities that you need to be mentioned.
Similarities between motorways and dual carriageway
A common misunderstanding is that motorways can’t have two lanes and that dual carriageways can’t have three. This is not true.
Though typically you might expect motorways to have three lanes and dual carriageways to only have two, some motorways only have two lanes and a hard shoulder while some dual carriageways have three.
As well as the number of lanes they can have, motorways and dual carriageways have a number of similarities, including:
▪ Both are separated by barriers in the central reservation
▪ Both have a top speed limit of 70 mph
▪ Both are usually accessed by a slip road