Variable-message sign

A variable- (also changeable-, electronic-, or dynamic-) message sign, often abbreviated VMS, CMS, or DMS, and in the UK known as a matrix sign,is an electronic traffic sign often used on roadways to give travellers information about special events. Such signs warn of traffic congestion, accidents, incidents such as terrorist attacks, AMBER/Silver/Blue Alerts, roadwork zones, or speed limits on a specific highway segment. In urban areas, VMS are used within parking guidance and information systems to guide drivers to available car parking spaces. They may also ask vehicles to take alternative routes, limit travel speed, warn of duration and location of the incidents, or just inform of the traffic conditions.A single row matrix LED sign on Katunayake Expressway in Colombo, Sri LankaA three row fixed character matrix LED sign warns 'Avoid London - Area Closed - Turn On Radio' following the 7 July 2005 London bombingsEurope's largest Dynamic Route Guidance System, in Nuremberg, Germany (hybrid rotating prism and row matrix LED)A full matrix multicolor LED variable message sign on the motorway Otoyol 3, Istanbul Shows that Mahmutbey Toll Gates, Bahçeşehir Area and Altınşehir Area's are green.A dual row matrix LED sign on National Highway 4, in Bangalore, IndiaA row matrix LED sign on an interchange of a German Autobahn with side graphics display.A hybrid row matrix and full matrix sign on Highway 401 in Ontario, CanadaA full matrix walk-in cabinet LED sign (manufactured by Skyline Products) displaying travel times on Interstate 70 north of Evergreen, Colorado.A dual row matrix LED sign in Manhattan reminding motorists to drive safelyAn LED sign on the New Jersey Turnpike displaying a warning about congestion aheadA set of LED signs on Interstate 90 in Mercer Island, Washington that warn of an upcoming lane closure due to a collision. Normally, these signs display variable speed limits that are adjusted during rush hour.A variable-message sign tells drivers that a section of the Hidaka Expressway in Hokkaido, Japan is damaged after the 2018 Hokkaido Eastern Iburi earthquake. A variable- (also changeable-, electronic-, or dynamic-) message sign, often abbreviated VMS, CMS, or DMS, and in the UK known as a matrix sign,is an electronic traffic sign often used on roadways to give travellers information about special events. Such signs warn of traffic congestion, accidents, incidents such as terrorist attacks, AMBER/Silver/Blue Alerts, roadwork zones, or speed limits on a specific highway segment. In urban areas, VMS are used within parking guidance and information systems to guide drivers to available car parking spaces. They may also ask vehicles to take alternative routes, limit travel speed, warn of duration and location of the incidents, or just inform of the traffic conditions. VMS's were deployed at least as early as the 1950s on the New Jersey Turnpike. The NJ Turnpike's signs of that period, and up to around 2012, were capable of displaying a few messages in neon, all oriented around warning drivers to slow down: 'REDUCE SPEED', followed by a warning of either construction, accident, congestion, ice, snow, or fog at a certain distance ahead. The New Jersey Turnpike Authority replaced those signs (along with 1990s-vintage dot-matrix VMS's along the Garden State Parkway) with more flexible electronic signs between 2010 and 2016. The current VMS systems are largely deployed on freeways, trunk highways, or in work zones. On the interchange of I-5 and SR 120 in San Joaquin County, California, an automated visibility and speed warning system was installed in 1996 to warn traffic of reduced visibility due to fog (where tule fog is a common problem in the winter), and of slow or stopped traffic. Message Signs were deployed in Ontario during the 1990s in the Greater Toronto Area and are now being upgraded on 400 series Highways in the GTA as well as two pilot secondary highways in northeastern Ontario. Early variable message signs included static signs with words that would illuminate (often using neon tubing) indicating the type of incident that occurred, or signs that used rotating prisms (trilons) to change the message being displayed. These were later replaced by dot matrix displays typically using eggcrate, fiber optic, or flip-disc technology, which were capable of displaying a much wider range of messages than earlier static variable message signs. Since the late 1990s, the most common technology used in new installations for variable message signs are LED displays. In recent years, some newer LED variable message signs have the ability to display colored text and graphics.