Longman Dictionary of Contemporary English
Wiktionary
n. (context UK English) A road in which the two directions of traffic are separated by a central barrier or strip of land, known as a central reservation or median.
WordNet
n. a highway divided down the middle by a barrier that separates traffic going in different directions; "in England they call a divided highway a dual carriageway" [syn: divided highway]
Wikipedia
A dual carriageway ( North American English: divided highway) is a class of highway with carriageways for traffic travelling in opposite directions separated by a central reservation (North American English: median). Roads with two or more carriageways which are designed to higher standards with controlled access are generally classed as motorways, freeways, etc., rather than dual carriageways.
A road without a central reservation is a single carriageway (North American English: undivided highway) regardless of the number of lanes. Dual carriageways have improved road traffic safety over single carriageways and typically have higher speed limits as a result. In some places, express lanes and local/collector lanes are used within a local-express-lane system to provide more capacity and to smooth traffic flows for longer-distance travel.
Usage examples of "dual carriageway".
Eventually, at the end of one of these muttered scrambles, I found that I was beside a busy dual carriageway exactly opposite the blue-roofed sprawl I had begun searching for an hour earlier.
It was through the southern end of this that the traffic was now attempting to pass: a jumble of stodgy towers and lowflung contemporary hutments which stretched along the dual carriageway almost as far as the amiable sanatorium settlement of Bad Godesberg, whose principal industry, having once been bottled water, is now diplomacy.
The delivery man had left his van on the grass verge by the dual carriageway.
Then headed out to his car, drove through the quiet streets and quieter countryside, hitting dual carriageway and giving the Saab's engine a proper work-out as he sped south towards Edinburgh.
They cleared the tunnel and cloverleaf and sped down the dual carriageway for London.
The moment the column of traffic blocked behind the artic entered the dual carriageway section, the other car drivers joyfully sped past the lorry and Murphy had it all to himself.
Near Ormskirk the dual carriageway merged into a single road, and grew dimmer.
He shifted gears fast, and took them up onto the dual carriageway into Oxford, a different route, Gini noted, from the one he had taken before.
She called up a display on the console and studied it as the car sped along the abbreviated length of dual carriageway leading out of Gaillimh Metro to the narrower road skirting the coast of the great landlocked sea.