A single carriageway
(North American English undivided highway
) is a road
with 1, 2 or more lanes
arranged within a single carriageway
(North American English: roadway) with no central reservation
(North American English: median) to separate opposing flows of traffic. Two-lane road
or two-lane highway
are single carriageway with one lane for each direction. A single track road
has a a single lane with passing places for traffic in both directions. Road traffic safety
is generally worse for high-speed single carriageway roads than for dual carriageway
(North America English: divided highways) due to the lack of separation between traffic moving in opposing directions.
The term single carriageway is used for roads in the Republic of Ireland
. Speed limits
on single carriageway roads vary depending on their classification: national primary roads
and national secondary roads
have a general speed limit of while regional roads
and local roads
have a general speed limit of . In urban areas, the general speed limit is .
The maximum UK speed limit
for single carriageway roads is lower than the maximum for dual-carriageway roads. The 'national speed limit', which is lower for built-up
areas, only applies in places where a lower numeric speed limit is not in place. The UK has one major single carriageway motorway, the A38
, but a number of link roads at motorway interchanges are single carriageway.
In the U.S. the expression "undivided... Read More