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A carriageway (
British English
British English (BrE, en-GB, or BE) is, according to Lexico, Oxford Dictionaries, "English language, English as used in Great Britain, as distinct from that used elsewhere". More narrowly, it can refer specifically to the English language in ...
) or roadway (
North American English
North American English (NAmE, NAE) is the most generalized variety of the English language as spoken in the United States and Canada. Because of their related histories and cultures, plus the similarities between the pronunciations (accents), v ...
)
consists of a width of
road
A road is a linear way for the conveyance of traffic that mostly has an improved surface for use by vehicles (motorized and non-motorized) and pedestrians. Unlike streets, the main function of roads is transportation.
There are many types of ...
on which a vehicle is not restricted by any physical barriers or separation to move
laterally. A carriageway generally consists of a number of
traffic lanes together with any associated
shoulder, but may be a sole lane in width (for example, a highway
offramp
In the field of road transport, an interchange (American English) or a grade-separated junction (British English) is a road junction that uses grade separations to allow for the movement of traffic between two or more roadways or highways, using ...
).
Description
A
single carriageway road (North American English: undivided highway) has one carriageway with 1, 2 or more lanes together with any associated
footways (North American English: sidewalk) and
road verge
A road is a linear way for the conveyance of traffic that mostly has an improved surface for use by vehicles (motorized and non-motorized) and pedestrians. Unlike streets, the main function of roads is transportation.
There are many types of ...
s (North American English: tree belt). A
dual carriageway
A dual carriageway ( BE) or divided highway ( AE) is a class of highway with carriageways for traffic travelling in opposite directions separated by a central reservation (BrE) or median (AmE). Roads with two or more carriageways which are ...
road (North American English: divided highway) has two roadways separated by a
central reservation
The median strip, central reservation, roadway median, or traffic median is the reserved area that separates opposing lanes of traffic on divided roadways such as divided highways, dual carriageways, freeways, and motorways. The term also a ...
(North American English: median). A
local-express lane system (also called collector-express or collector-distributor) has more than two roadways, typically two sets of 'local lanes' or 'collector lanes' and also two sets of 'express lanes'. "Cars only" lanes may be physically separated from those open to mixed traffic including trucks and buses. The
New Jersey Turnpike
The New Jersey Turnpike (NJTP) is a system of controlled-access highways in the U.S. state of New Jersey. The turnpike is maintained by the New Jersey Turnpike Authority (NJTA).The Garden State Parkway, although maintained by NJTA, is not consi ...
(
I-95) in the United States, uses this design from the
Pennsylvania Turnpike
The Pennsylvania Turnpike (Penna Turnpike or PA Turnpike) is a toll highway operated by the Pennsylvania Turnpike Commission (PTC) in the U.S. state of Pennsylvania. A controlled-access highway, it runs for across the state. The turnpike's we ...
to its northern terminus at the
George Washington Bridge in
Fort Lee.
High-occupancy vehicle lanes may also be physically separated from the remainder of the general traffic lanes as a distinct roadway. Some cities such as
Pittsburgh, Pennsylvania
Pittsburgh ( ) is a city in the Commonwealth (U.S. state), Commonwealth of Pennsylvania, United States, and the county seat of Allegheny County, Pennsylvania, Allegheny County. It is the most populous city in both Allegheny County and Wester ...
, have many bus-only roadways to alleviate congestion related to public transit buses, despite its very challenging topography which severely limits the extent to which arterial roadways can be added or augmented.
See also
*
Dual carriageway
A dual carriageway ( BE) or divided highway ( AE) is a class of highway with carriageways for traffic travelling in opposite directions separated by a central reservation (BrE) or median (AmE). Roads with two or more carriageways which are ...
*
Frontage road / lane
*
Geometric design of roads
The geometric design of roads is the branch of highway engineering concerned with the positioning of the physical elements of the roadway according to standards and constraints. The basic objectives in geometric design are to optimize efficienc ...
*
Road terminology
References
{{reflist
Road infrastructure
de:Straßenquerschnitt#Fahrbahn