Mandatory sign
Encyclopedia
Mandatory signs are road signs which are used to set the obligations of all traffic which use a specific area of road. Unlike prohibitory or restrictive signs
, mandatory signs tell traffic what it must do, rather than must not do. Most mandatory road signs are circular, may use white symbols on a blue background with white border or black symbols on a white blackground with a red border, although the latter is also associated with prohibitory signs.
Mandatory signs are a subset of the regulatory sign
group as defined by the United Nations Economic and Social Council
in the Vienna Convention on Road Signs and Signals
of 1968, and are often seen not just on their own, but used in conjunction with other signs, traffic light
s and bollard
s as a form of visual shorthand within these objects.
In Vienna signatories, the mandatory sign is either a light blue circle with a white border or a white circle with a red border. The sign must be at least 60 cm (1.96 ft) across on rural roads, or 40 cm (1.31 ft) in built-up areas, although mandatory signs incorporated in traffic lights, bollards or larger road signs can be as little as 30 cm (0.98 ft) in diameter.
The mandatory sign group is not used in the United States
and Canada
, who are not signatories to the Vienna Convention; both countries consider them kinds of regulatory signs. Some Canadian provinces differentiate mandatory signs from prohibitive ones by enclosing the symbols in a green rather than red border, although this can indicate either a mandatory or a warning sign
, while in the U.S., the only difference between a prohibitory sign and a mandatory one is that a mandatory sign includes the word "only" at the bottom of the plate instead of crossing out the pictogram.
ways, bus lane
s, taxi
lanes, HOV lanes and snow mobile tracks can also be designated with mandatory signs. When a specific area of roadway is designated with a mandatory sign specifying a vehicle type, all traffic of this type must use this area if possible. These signs can be combined by putting one pictogram above the other. If the pictograms are side-by-side however, with the sign divided by a white vertical line, each type of vehicle must stay within the lane indicated by the sign. A red line through a mandatory sign indicates not that a vehicle of a specific type is prohibited from entering the designated area, but that the area is now deregulated and any vehicle may use it.
s can also be defined using mandatory road signs, although such signs are rare in most countries; the U.S., which does not use mandatory signs, instead places minimum speed limits on the same type of panel as maximum speed limits.
Prohibitory traffic sign
Prohibitory traffic signs are used to prohibit certain types of manoeuvres or some types of traffic.-No entry:No admittance to unauthorised personnel, usually shown as a red circle with a white rectangle across its face.-Speed limits:...
, mandatory signs tell traffic what it must do, rather than must not do. Most mandatory road signs are circular, may use white symbols on a blue background with white border or black symbols on a white blackground with a red border, although the latter is also associated with prohibitory signs.
Design
Regulatory sign
One type of regulatory signs are traffic signs intended to instruct road users on what they must or should do under a given set of circumstances. Other types may be signs located on streets and in parking lots having to do with parking, signs in public parks and on beaches or on or in...
group as defined by the United Nations Economic and Social Council
United Nations Economic and Social Council
The Economic and Social Council of the United Nations constitutes one of the six principal organs of the United Nations and it is responsible for the coordination of the economic, social and related work of 14 UN specialized agencies, its functional commissions and five regional commissions...
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...
of 1968, and are often seen not just on their own, but used in conjunction with other signs, 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...
s and bollard
Bollard
A bollard is a short vertical post. Originally it meant a post used on a ship or a quay, principally for mooring. The word now also describes a variety of structures to control or direct road traffic, such as posts arranged in a line to obstruct the passage of motor vehicles...
s as a form of visual shorthand within these objects.
In Vienna signatories, the mandatory sign is either a light blue circle with a white border or a white circle with a red border. The sign must be at least 60 cm (1.96 ft) across on rural roads, or 40 cm (1.31 ft) in built-up areas, although mandatory signs incorporated in traffic lights, bollards or larger road signs can be as little as 30 cm (0.98 ft) in diameter.
The mandatory sign group is not used in the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
and 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...
, who are not signatories to the Vienna Convention; both countries consider them kinds of regulatory signs. Some Canadian provinces differentiate mandatory signs from prohibitive ones by enclosing the symbols in a green rather than red border, although this can indicate either a mandatory or a warning sign
Warning sign
A traffic warning sign is a type of traffic sign that indicates a hazard ahead on the road that may not be readily apparent to a driver.In most countries, they usually take the shape of an equilateral triangle with a white background and a thick red border...
, while in the U.S., the only difference between a prohibitory sign and a mandatory one is that a mandatory sign includes the word "only" at the bottom of the plate instead of crossing out the pictogram.
Segregation of roads
Mandatory road signs can be used to allocate certain areas to specific vehicles - the Vienna Convention explicitly mentions footpaths, cyclepaths and bridleways, but tramTram
A tram is a passenger rail vehicle which runs on tracks along public urban streets and also sometimes on separate rights of way. It may also run between cities and/or towns , and/or partially grade separated even in the cities...
ways, bus lane
Bus lane
A bus lane or bus only lane is a lane restricted to buses, and generally used to speed up public transport that would be otherwise held up by traffic congestion...
s, taxi
Taxicab
A taxicab, also taxi or cab, is a type of vehicle for hire with a driver, used by a single passenger or small group of passengers, often for a non-shared ride. A taxicab conveys passengers between locations of their choice...
lanes, HOV lanes and snow mobile tracks can also be designated with mandatory signs. When a specific area of roadway is designated with a mandatory sign specifying a vehicle type, all traffic of this type must use this area if possible. These signs can be combined by putting one pictogram above the other. If the pictograms are side-by-side however, with the sign divided by a white vertical line, each type of vehicle must stay within the lane indicated by the sign. A red line through a mandatory sign indicates not that a vehicle of a specific type is prohibited from entering the designated area, but that the area is now deregulated and any vehicle may use it.
Instruction
Mandatory signs can also be used to issue instructions to all vehicles - common examples include "pass on this side" signs seen at roadworks, and "compulsory roundabout" signs seen at mini-roundabouts. Other signs of the type include "attach snow chains" and "remove snow chains" seen at the entry and exit points of mountainous areas, and "compulsory direction for vehicles carrying dangerous loads", used to divert vehicles carrying explosives or poisonous chemicals away from areas with open flames such as oil refineries. Minimum speed limitSpeed limit
Road speed limits are used in most countries to regulate the speed of road vehicles. Speed limits may define maximum , minimum or no speed limit and are normally indicated using a traffic sign...
s can also be defined using mandatory road signs, although such signs are rare in most countries; the U.S., which does not use mandatory signs, instead places minimum speed limits on the same type of panel as maximum speed limits.