HOME

TheInfoList



OR:

A destination sign (North American English) or destination indicator/destination blind (British English) is a sign mounted on the front, side or rear of a
public transport Public transport (also known as public transportation, public transit, mass transit, or simply transit) is a system of transport for passengers by group travel systems available for use by the general public unlike private transport, typical ...
vehicle, such as a
bus A bus (contracted from omnibus, with variants multibus, motorbus, autobus, etc.) is a road vehicle that carries significantly more passengers than an average car or van. It is most commonly used in public transport, but is also in use for cha ...
, tram/streetcar or light rail vehicle, that displays the vehicle's route number and destination, or the route's number and name on transit systems using route names. The main such sign, mounted on the front of the vehicle, usually located above (or at the top of) the windshield, is often called the headsign, most likely from the fact that these signs are located on the front, or head, end of the vehicle. Depending on the type of the sign, it might also display intermediate points on the current route, or a road that comprises a significant amount of the route, especially if the route is particularly long and its final terminus by itself is not very helpful in determining where the vehicle is going.


Technology types

Several different types of technology have been used for destination signs, from simple rigid placards held in place by a frame or clips, to
rollsign A destination sign (North American English) or destination indicator/destination blind (British English) is a sign mounted on the front, side or rear of a public transport vehicle, such as a bus, tram/streetcar or light rail vehicle, that di ...
s, to various types of computerized,
electronically The field of electronics is a branch of physics and electrical engineering that deals with the emission, behaviour and effects of electrons using Electronic component, electronic devices. Electronics uses Passivity (engineering), active devices ...
controlled signs, such as flip-dot, LCD or
LED A light-emitting diode (LED) is a semiconductor Electronics, device that Light#Light sources, emits light when Electric current, current flows through it. Electrons in the semiconductor recombine with electron holes, releasing energy i ...
displays. All of these can still be found in use today, but most transit-vehicle destination signs now in use in North America and Europe are electronic signs. In the US, the
Americans with Disabilities Act of 1990 The Americans with Disabilities Act of 1990 or ADA () is a civil rights law that prohibits discrimination based on disability. It affords similar protections against discrimination to Americans with disabilities as the Civil Rights Act of 19 ...
specifies certain design criteria for transit-vehicle destination signs, such as maximum and minimum character height-to-width ratio and contrast level, to ensure the signs are sufficiently readable to visually impaired persons.Destination and route signs
(guidelines for), section 39 withi
Part 38
(Accessibility Specifications for Transportation Vehicles) of the U.S.
Americans with Disabilities Act of 1990 The Americans with Disabilities Act of 1990 or ADA () is a civil rights law that prohibits discrimination based on disability. It affords similar protections against discrimination to Americans with disabilities as the Civil Rights Act of 19 ...
.
In the 2010s, LED signs have replaced flip-dot signs as the most common type of destination sign in new buses and
rail transit Urban rail transit is an all-encompassing term for various types of local rail systems providing passenger service within and around urban or suburban areas. The set of urban rail systems can be roughly subdivided into the following categories, ...
vehicles.


Rollsign

For many decades, the most common type of multiple-option destination sign was the rollsign (or ''bus blind'', ''curtain sign'', ''destination blind'', or ''tram scroll''): a roll of flexible material with pre-printed route number/letter and destinations (or route name), which is turned by the vehicle operator at the end of the route when reversing direction, either by a hand crank or by holding a switch if the sign mechanism is motorized. These rollsigns were usually made of
linen Linen () is a textile made from the fibers of the flax plant. Linen is very strong, absorbent, and dries faster than cotton. Because of these properties, linen is comfortable to wear in hot weather and is valued for use in garments. It also ...
until
Mylar BoPET (biaxially-oriented polyethylene terephthalate) is a polyester film made from stretched polyethylene terephthalate (PET) and is used for its high tensile strength, chemical and dimensional stability, transparency, reflectivity, gas and aro ...
(a type of PET film) became the most common material used for them, in the 1960s/70s. They can also be made of other material, such as
Tyvek Tyvek () is a brand of synthetic flashspun high-density polyethylene fibers. The name "Tyvek" is a registered trademark of the American multinational chemical company DuPont, which discovered and commercialized Tyvek in the late 1950s and early ...
. In the 1990s rollsigns were still commonly seen in older
public transport Public transport (also known as public transportation, public transit, mass transit, or simply transit) is a system of transport for passengers by group travel systems available for use by the general public unlike private transport, typical ...
vehicles, and were sometimes used in modern vehicles of that time. Since the 1980s, they have largely been supplanted by electronic signs. A
digital display A display device is an output device for presentation of information in visual or tactile form (the latter used for example in tactile electronic displays for blind people). When the input information that is supplied has an electrical signal t ...
may be somewhat less readable, but is easier to change between routes/destinations and to update for changes to a transit system's route network. However, given the long life of public transit vehicles and of sign rolls, if well made, some transit systems continue to use these devices in the 2010s. The roll is attached to metal tubes at the top and bottom, and flanges at the ends of the tubes are inserted into a mechanism which controls the rolling of the sign. The upper and lower rollers are positioned sufficiently far apart to permit a complete "reading" (a destination or route name) to be displayed, and a strip light is located behind the blind to illuminate it at night. When the display needs to be changed, the driver/operator/conductor turns a handle/crank—or holds a switch if the sign mechanism is motorized—which engages one roller to gather up the blind and disengages the other, until the desired display is found. A small viewing window in the back of the signbox (the compartment housing the sign mechanism) permits the driver to see an indication of what is being shown on the exterior. Automatic changing of rollsign/blind displays, through electronic control, has been possible since at least the 1970s, but is an option that primarily has been used on rail systems—where a
metro Metro, short for metropolitan, may refer to: Geography * Metro (city), a city in Indonesia * A metropolitan area, the populated region including and surrounding an urban center Public transport * Rapid transit, a passenger railway in an urba ...
train or
articulated tram Trams have been used since the 19th century, and since then, there have been various uses and designs for trams around the world. This article covers the many design types, most notably the articulated, double-decker, drop-centre, low-floor, si ...
can have several separate signboxes each—and only infrequently on buses, where it is comparatively easy for the driver to change the display. These signs are controlled by a computer through an interface in the driver's cabin.
Barcode A barcode or bar code is a method of representing data in a visual, machine-readable form. Initially, barcodes represented data by varying the widths, spacings and sizes of parallel lines. These barcodes, now commonly referred to as linear or o ...
s are printed on the reverse of the blind, and as the computer rolls the blind an optical sensor reads the barcodes until reaching the code for the requested display. The on-board computer is normally programmed with information on the order of the displays, and can be programmed using the
non-volatile memory Non-volatile memory (NVM) or non-volatile storage is a type of computer memory that can retain stored information even after power is removed. In contrast, volatile memory needs constant power in order to retain data. Non-volatile memory typic ...
should the blind/roll be changed. Although these sign systems are normally accurate, over time the blind becomes dirty and the computer may not be able to read the markings well, leading occasionally to incorrect displays. For buses, this disadvantage is outweighed by the need (compared to manual) to change each destination separately; if changing routes, this could be up to seven different blinds. Automatic-setting rollsigns are common on many light rail and subway/metro systems in North America. Most Transport for London buses use a standard system with up & down buttons to change the destination shown on the blinds & a manual override using a crank. The blind system is integrated with a system controlling announcements & passenger information, which uses satellites to download stop data in a sequential order. It uses GPS to determine that a bus has departed a stop, and announce the next stop.


Plastic sign

Plastic signs are inserted by the driver into the slot at the front of the bus before a service run. In Hong Kong, plastic signs had been used since the mid-90s on
Kowloon Motor Bus The Kowloon Motor Bus Company (1933) Limited (KMB) is a bus company operating franchised services in Hong Kong. It is the largest bus company in Hong Kong by fleet size and number of bus routes. It is a subsidiary of Transport International. ...
(KMB) and
Long Win Bus Long Win Bus Company Limited (LWB; ) is a bus company operating franchised services in Hong Kong. It provides bus service between Hong Kong International Airport, North Lantau New Town and the New Territories. It is a subsidiary of Transport In ...
(LWB) buses to replace rollsigns on the existing fleet, and became a standard equipment until 2000 when electronic display became mainstream, with the exception of single decker buses, presumably because the number of destinations in the network was so large that rolling the destination between every trip was impractical. These buses were equipped with a destination sign slot which 2 plastic destination signs could be placed in it, such that the driver could press a button to flip them at the terminus, and one slot at the front, side and back of the bus respectively for the route number only. All buses with plastic signs were retired in 2017 upon completing 18 years of service.


Flip-disc display

In the United States, the first electronic destination signs for buses were developed by Luminator in the mid-1970s"Sign of the Times: Transit signs have evolved from curtain signs to the first electronic sign introduced by Luminator to the present ADA-regulated visual and audio signs". ''Mass Transit'' magazine, January–February 1993, pp. 30–32. Fort Atkinson, WI (USA): Cygnus Publishing. ISSN 0364-3484. and became available to transit operators in the late 1970s, but did not become common until the 1980s. These were flip-disc, or "flip-dot", displays. Some transit systems still use these today.


Flap display

Another technology that has been employed for destination signs is the
split-flap display A split-flap display, or sometimes simply a flap display, is a digital electromechanical display device that presents changeable alphanumeric text, and occasionally fixed graphics. Often used as a public transport timetable in airports or ...
, or ''Solari'' display, but outside
Italy Italy ( it, Italia ), officially the Italian Republic, ) or the Republic of Italy, is a country in Southern Europe. It is located in the middle of the Mediterranean Sea, and its territory largely coincides with the homonymous geographical re ...
, this technology was never common for use in transit vehicles. Such displays were more often used at transit hubs to display arrival and departure information, rather than as destination signs on transit vehicles.


Electronic displays

Most present-day destination indicator signs consist of
liquid crystal display A liquid-crystal display (LCD) is a flat panel display, flat-panel display or other Electro-optic modulator, electronically modulated optical device that uses the light-modulating properties of liquid crystals combined with polarizers. Liqui ...
(LCD) or
light-emitting diode A light-emitting diode (LED) is a semiconductor device that emits light when current flows through it. Electrons in the semiconductor recombine with electron holes, releasing energy in the form of photons. The color of the light (cor ...
(LED) panels that can show animated text, colors (in the case of LED signs), and a potentially unlimited number of routes (so long as they are programmed into the vehicle's sign controller unit; some sign controller units may also allow the driver to write the route number and the destination text through a keypad if required). In many systems, the vehicle has three integrated signs in the system, the front sign over the windshield, the side sign over the passenger entrance, both showing the route number and destination, and a rear sign usually showing the route number. An internal sign, that could also provide different kinds of information such as the current stop and the next one, aside from the route number and destination, may also be installed. Some such signs also have the capability of changing on-the-fly as the vehicle moves along its route, with the help of
GPS The Global Positioning System (GPS), originally Navstar GPS, is a Radionavigation-satellite service, satellite-based radionavigation system owned by the United States government and operated by the United States Space Force. It is one of t ...
technology, serial interfaces and a
vehicle tracking system A vehicle tracking system combines the use of automatic vehicle location in individual vehicles with software that collects these fleet data for a comprehensive picture of vehicle locations. Modern vehicle tracking systems commonly use GPS or G ...
.


See also

*
Platform display A platform display, destination display or train describer (British English) is supplementing the destination sign on arriving trains giving passengers an advance information. Historically they did only show the next destination and sometimes the ...


References


External links

Rollsign Gallery, showing the history of public transit through their destination signs – USA, Canada, overseas
www.rollsigngallery.com
{{DEFAULTSORT:Destination Sign Public transport information systems Display technology Signage