One-way traffic
From Wikipedia, the free encyclopedia
A one-way street is a street on which vehicles can only move in one direction. On this type of street a sign is posted showing which direction the vehicles can move in: commonly an upward arrow, or on a T junction where the main road is one-way, an arrow to the left or right. At the end of the street through which vehicles may not enter, a prohibitory traffic sign "Do Not Enter" or "No Entry" sign is posted, e.g. with that text, or a round red sign with a white horizontal bar. Sometimes one portion of a street is one-way, the other portion two-way. An advantage of one-way streets is that drivers do not have to watch for cars coming in the opposite direction on this type of street.
One-way streets may also be part of a one-way system, which facilitates a smoother flow of traffic through, for example, a city centre grid. This is achieved by arranging one-way streets that cross in such a fashion as to eliminate right turns (for driving on left) or left turns (for driving on right). Traffic light systems at such junctions are also simpler.
The first one-way street was established in London on 23 August 1617[citation needed]. Albemarle Street in central London, the location of the Royal Institution, was designated London's first one-way street because the public lectures there were so popular [1]. The first one-way streets in Paris were the Rue de Mogador and the Rue de la Chaussée-d'Antin, created on 13 December 1909.
[edit] Reasons for being one-way
- Street is too narrow for movement in both directions-in this case parking will only be allowed on one side of the street or not at all.
- To prevent drivers from cutting through a residential street to bypass traffic lights or other things that require vehicles to stop.
- Part of a one-way pair of two parallel one-way streets in opposite directions.
- For a proper functioning of a system of paid parking or other paid access.
- To keep traffic low, especially if the street is historic.
[edit] One-way traffic of people
Sometimes there is one-way walking for people, for smooth traffic flow, or in the case of entrance checks (such as ticket checks) and exit checks (e.g. the check-out in a shop). They may be outdoors, e.g. an extra exit of a zoo, or in a building, or in a vehicle, e.g. a tram.
In addition to just signs, there may be various forms and levels of enforcement, such as:
- personnel
- a turnstile; turnstile jumping is possible
- a High Entrance/Exit Turnstile (HEET)
- a door or gate that can only be opened from one side (a manual or electric lock, or simply a door that is pushed open and has no doorknob on the other side), or automatically opens from one side; with help from someone on the other side, it can usually conveniently be passed in the "wrong" direction. Examples:
- entrance of a shop
- an emergency exit; it may activate an alarm, useful both for proper and improper use of the door
- an escalator; the escalator can be passed in opposite direction, climbing up or down the stairs faster than it moves
- a one-way revolving door
Sometimes a "soft" traffic control system is supported by personnel keeping an eye on things.
Sometimes a door or gate can be opened freely from one side, and only with a key or by inserting a coin from the other side (house door, door with a coin slot, e.g. giving entrance to a pay toilet). The latter can be passed without paying when somebody else leaves, and by multiple persons if only one pays (as opposed to a coin-operated turnstile).
