Editing Traffic (section)

===One-way roadways===
[[File:Anawrahta road traffic.jpg|thumb|One-way traffic on Anawrahta road, [[Yangon]]]]
{{Main article|One-way traffic|Dual carriageway}}

In order to increase traffic capacity and safety, a route may have two or more separate roads for each direction of traffic. Alternatively, a given road might be declared ''one-way''.

====High-speed roads====
{{Main article|Limited-access road|Controlled-access highway}}

In large cities, moving from one part of the city to another by means of ordinary streets and avenues can be time-consuming since traffic is often slowed by [[grade separation#Roads|at-grade junctions]], tight turns, narrow marked lanes and lack of a minimum [[speed limit]]. Therefore, it has become common practice for larger cities to build roads for faster [[through traffic]]. There are two different types of roads used to provide high-speed access across urban areas:
*The [[controlled-access highway]] (''freeway'' or ''motorway'') is a divided multi-lane highway with fully controlled access and grade-separated intersections (no cross traffic). Some freeways are called ''[[Controlled-access highway|expressways]]'', ''super-highways'', or ''[[turnpike (disambiguation)|turnpike]]s'', depending on local usage. Access to freeways is fully controlled; entering and leaving the freeway is permitted only at grade-separated interchanges.
*The [[limited-access road]] (often called ''expressway'' in areas where the name does not refer to a freeway or motorway) is a lower-grade type of road with some or many of the characteristics of a controlled-access highway: usually a broad multi-lane avenue, frequently divided, with some [[grade separation]] at intersections.

[[Motor vehicle]] [[driving|drivers]] wishing to travel over great distances within the city will usually take the freeways or expressways in order to minimize travel time. When a crossing road is at the same [[Grade separation|grade]] as the freeway, a bridge (or, less often, an [[underpass]]) will be built for the crossing road. If the freeway is elevated, the crossing road will pass underneath it.

Minimum speed signs are sometimes posted (although increasingly rare) and usually indicate that any vehicle traveling slower than {{convert|40|mph|abbr=on}} should indicate a slower speed of travel to other motor vehicles by engaging the vehicle's four-way flashing lights.  Alternative slower-than-posted speeds may be in effect, based on the posted speed limit of the highway/freeway.

Systems of freeways and expressways are also built to connect distant and regional cities, notable systems include the [[Interstate highways]], the [[German Autobahn|Autobahnen]] and the [[Expressways of China|Expressway Network of the People's Republic of China]].

==== One-way streets ====
{{Main|One-way traffic}}
In more sophisticated systems such as large cities, this concept is further extended: some streets are marked as being ''one-way'', and on those streets all traffic must flow in only one direction.  Pedestrians on the sidewalks are generally not limited to one-way movement.  Drivers wishing to reach a destination they have already passed must return via other streets.  One-way streets, despite the inconveniences to some individual drivers, can greatly improve traffic flow since they usually allow traffic to move faster and tend to simplify intersections.