Lane control lights
Encyclopedia
Lane control lights are a specific type of traffic light
Traffic light
Traffic lights, which may also be known as stoplights, traffic lamps, traffic signals, signal lights, robots or semaphore, are signalling devices positioned at road intersections, pedestrian crossings and other locations to control competing flows of traffic...

 used to manage traffic on a multi-way road or highway. Typically they allow or forbid traffic to use one or more of the available lanes by the use of Green lights or arrows (to permit) or by red lights or crosses (to prohibit). When used, they are usually repeated at regular distances to provide a continuous reminder of the lane status to drivers.

On certain multiple-lane highways, one or more lanes may be designated as counterflow lanes, meaning that the direction of traffic in those lanes can be reversed at any time (see also reversible lane
Reversible lane
A reversible lane , called a counterflow lane or contraflow lane in transport engineering nomenclature, is a lane in which traffic may travel in either direction, depending on certain conditions...

). Sometimes this is done as a way of managing rush hour traffic (one or more central lanes may flow inbound in the morning and outbound in the evening), in other cases the lanes are reversed only in unusual circumstances (such as a traffic accident or road construction closing one or more of the lanes).

Lane control signals around the world follow their own universal pattern, as specified in the Vienna Convention on Road Signs and Signals
Vienna Convention on Road Signs and Signals
The Vienna Convention on Road Signs and Signals is an international treaty designed to increase road safety and aid international road traffic by standardising the signing system for road traffic in use internationally.This convention was agreed upon by the United Nations Economic and Social...

. Typical signals include a green downward arrow, used to indicate a lane which is open to traffic facing the signal, a red cross, which indicates a lane is either reserved for opposing traffic or closed to traffic in both directions, and a flashing amber circle, arrow or cross, indicating to traffic facing the signal to immediately clear the lane.

Unlike regular traffic lights, lane control signals either have one face each to indicate all lane conditions (the so-called "searchlight" configuration), or separate faces for each condition (as illustrated). Lane control signals of the latter type are usually placed horizontally. Signals that may indicate other conditions for roads without counterflow lanes also exist, such as those that indicate different speed limits for different lanes.

Examples

In the Australian state of Victoria
Victoria (Australia)
Victoria is the second most populous state in Australia. Geographically the smallest mainland state, Victoria is bordered by New South Wales, South Australia, and Tasmania on Boundary Islet to the north, west and south respectively....

, green and yellow are replaced by white, and there may be additional modes such as 'Centre lane turns only' at particular times of the day.

On Jarvis Street in Toronto
Toronto
Toronto is the provincial capital of Ontario and the largest city in Canada. It is located in Southern Ontario on the northwestern shore of Lake Ontario. A relatively modern city, Toronto's history dates back to the late-18th century, when its land was first purchased by the British monarchy from...

, Edmonton
Edmonton
Edmonton is the capital of the Canadian province of Alberta and is the province's second-largest city. Edmonton is located on the North Saskatchewan River and is the centre of the Edmonton Capital Region, which is surrounded by the central region of the province.The city and its census...

 and some other jurisdictions in Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...

 the lane control signals are employed without the use of an amber warning signal. Instead, the lane that is to undergo the direction reversal (the middle lane of a 5 lane downtown street) is marked with a red cross in both directions for a short period of time. This allows time for the lane to clear of traffic before a green arrow permits traffic in the reversed direction. However, Jarvis Street has been converted to a 4-lane arterial with bicycle lanes.

In Cleveland, Ohio
Cleveland, Ohio
Cleveland is a city in the U.S. state of Ohio and is the county seat of Cuyahoga County, the most populous county in the state. The city is located in northeastern Ohio on the southern shore of Lake Erie, approximately west of the Pennsylvania border...

 there is lane control on Euclid Avenue, for the new Euclid Avenue Bus Rapid Transit
Bus rapid transit
Bus rapid transit is a term applied to a variety of public transportation systems using buses to provide faster, more efficient service than an ordinary bus line. Often this is achieved by making improvements to existing infrastructure, vehicles and scheduling...

or BRT line. On the mast arms are three signals: Two lights are in the traditional yellow colour, and there is special traffic signal in black. Cars must use the lanes with the traditional yellow coloured lights, while the BRT uses the lane with the black coloured light. There is a penalty for cars if they use the bus lane.
The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
x
OK