A variable- message sign or message board, often abbreviated VMS, VMB, CMS, or DMS, and in the UK known as a matrix sign,
is an electronic traffic sign often used on roadways to give travelers 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, inform of the traffic conditions, or display general public safety messages.
LED matrix sign over I-94 in Saint Paul, Minnesota, advising of a road blockage during a winter storm
Early style of VMS on the New Jersey Turnpike using neon tubes, since replaced by new LED VMS signs. It is next to a vane variable speed-limit sign
Europe's largest Dynamic Route Guidance System Nuremberg, Germany
LED sign over Illinois State Route 390/Elgin-O'Hare Tollway in Roselle, Illinois showing remaining travel times
Traffic signs or road signs are signs erected at the side of or above roads to give instructions or provide information to road users. The earliest signs were simple wooden or stone milestones. Later, signs with directional arms were introduced, for example the fingerposts in the United Kingdom and their wooden counterparts in Saxony.
Fingerposts and other road signage in the English village of Sturminster Marshall, near Poole
Road sign for roundabout leading to highways 1, 2 and 3 in Mariehamn, Åland
Sign in Australia reminding drivers to carry adequate supplies before entering remote areas
Sign warning of cattle crossing in a rural road of Madeira Island, Portugal