 | The examples and perspective in this article may not represent a worldwide view of the subject.(August 2012) |
Road traffic control devices are markers, signs and signal devices used to inform, guide and control traffic, including pedestrians, motor vehicle drivers and bicyclists. These devices are usually placed adjacent, over or along the highways, roads, traffic facilities and other public areas that require traffic control.
Traffic signs are signs which use words and/or symbols to convey information to road users. These devices are made with retroreflective materials that reflect light from headlights back towards the driver's eyes. This is to achieve maximum visibility, especially at night.
Variable-message signs, or VMS, are electronic traffic control signs which can display different traffic messages according to the needs of a specific road. Permanent VMS displays are mounted on large sign structures overhead or alongside the road. These devices are often placed on urban freeways which have traffic problems. Portable CMS (PVMS) panels are usually mounted on trailers, although some may be carried by trucks. They are often used in work zones or other events that disrupt traffic. CMS devices also follow a uniform shape, design and color that were set by the Manual on Uniform Traffic Control Devices.
High-level warning devices are traffic control devices that are high enough to see over other vehicles, such as vehicle roofs, poles, and other places not lower than eight feet (2.4 m). These devices are also called "flag trees" because they feature two or three square fluorescent orange flags and, sometimes, a flashing warning light. This type of traffic control devices are used in work zones in high traffic density urban areas.
Channelizing devices are used to warn drivers and pedestrians and to guide them through a work zone. Common channelizing devices are traffic cones and drums. These types of traffic control devices are usually placed between traffic and road construction zones, or between opposing traffic streams.
Road surface markings are traffic control devices that are applied directly to the road surfaces. They are used to guide and channel traffic by designating lanes and indicating stopping points at intersections. Pavement markings may be permanent or removable.
Rumble strips are roughened surfaces that are either embossed or recessed. When a vehicle drives over them, they make a loud rumbling sound and vibration. They can be placed across traffic lanes to alert drivers that they are approaching a potentially hazardous location, such as a work zone, school zone, rail road crossing or an isolated intersection. They are used along the shoulders or centerlines of highways to alert drivers that they are leaving their traffic lane.
Traffic lights are traffic control signals used to alternately assign right-of-way to traffic moving in conflicting directions at an intersection. Traffic lights feature three different lights that conveys different meanings. The red light means that the vehicle facing the traffic light must come to a complete stop. A green light means that the vehicle facing the traffic light may proceed when it is safe to do so. A yellow light indicates that a red light will follow, and vehicle drivers must stop if it is safe to do so.
A pedestrian crossing is a place designated for pedestrians to cross a road, street or avenue. The term "pedestrian crossing" is also used in the Vienna and Geneva Conventions, both of which pertain to road signs and road traffic.
Traffic lights, traffic signals, or stoplights – also known as robots in South Africa – are signalling devices positioned at road intersections, pedestrian crossings, and other locations in order to control the flow of traffic.
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.
A warning sign is a type of sign which indicates a potential hazard, obstacle, or condition requiring special attention. Some are traffic signs that indicate hazards on roads that may not be readily apparent to a driver.
A cat's eye or road stud is a retroreflective safety device used in road marking and was the first of a range of raised pavement markers.
Traffic cones, also called pylons, witches' hats, road cones, highway cones, safety cones, caution cones, channelizing devices, construction cones, or just cones, are usually cone-shaped markers that are placed on roads or footpaths to temporarily redirect traffic in a safe manner. They are often used to create separation or merge lanes during road construction projects or automobile accidents, although heavier, more permanent markers or signs are used if the diversion is to stay in place for a long period of time.
A raised pavement marker is a safety device used on roads. These devices are usually made with plastic, ceramic, thermoplastic paint, glass or occasionally metal, and come in a variety of shapes and colors. Raised reflective markers, such as plastic, ceramic, or metal ones, include a lens or sheeting that enhances their visibility by retroreflecting automotive headlights, while glass road studs gather automotive headlights with a dome shape and reflect the lights with a reflective layer within. Some other names for specific types of raised pavement markers include convex vibration lines, Botts' dots, delineators, cat's eyes, road studs, or road turtles. Sometimes they are simply referred to as "reflectors".
Road surface marking is any kind of device or material that is used on a road surface in order to convey official information; they are commonly placed with road marking machines. They can also be applied in other facilities used by vehicles to mark parking spaces or designate areas for other uses. In some countries and areas, road markings are conceived as horizontal traffic signs, as opposed to vertical traffic signs placed on posts.
Botts' dots are round non-reflective raised pavement markers. In many parts of the US, Botts' dots are used, along with reflective raised pavement markers, to mark lanes on highways and arterial roads. They provide tactile and auditory feedback to drivers when moving across designated travel lanes, and are analogous to rumble strips.
Emergency vehicle equipment is any equipment fitted to, or carried by, an emergency vehicle, other than the equipment that a standard non-emergency vehicle is fitted with.
Road signs in Sweden are regulated in Vägmärkesförordningen, VMF (2007:90), and are to be placed 2 metres from the road with the sign 1.6 m from the base for motorized roads. Except for route numbers, there are a maximum of three signs on a pole, with the most important sign at the top. All signs have a reflective layer added on selected parts of the sign as is custom in European countries; most larger signs also have their own illumination.
Road signs in Thailand are standardized road signs similar to those used in other nations but much of it resembles road signage systems used in South American countries with certain differences, such as using a blue circle instead of a red-bordered white circle to indicate mandatory actions. Until the early 1980s, Thailand closely followed American, European, Australian, and Japanese practices in road sign design, with diamond-shaped warning signs and circular restrictive signs to regulate traffic. The Department of Railway maintains a standard on the typeface used in the sign, with custom made type for Thai text, and a small derivation of FHWA Series fonts typeface, which is used on American road signage, for Latin text.
A roadway departure is a type of incident that occurs when a vehicle leaves the roadway. Such incidents can lead to a single-vehicle collision.
In the United States, road signs are, for the most part, standardized by federal regulations, most notably in the Manual on Uniform Traffic Control Devices (MUTCD) and its companion volume the Standard Highway Signs (SHS).
An embedded flashing-light system or an in-pavement flashing-light system is a type of device that is used at existing or new pedestrian crosswalks to warn drivers of oncoming pedestrian traffic. The device usually consists of LED lights that are embedded into the roadway alongside the crosswalk and are oriented to face oncoming traffic. When a pedestrian approaches the crosswalk, the system is activated and the LED lights begin to flash simultaneously. These lights are programmed to flash for a period of time that is sufficient for an average pedestrian to cross.
Solar road studs are flashing solar cell powered LED low-maintenance lighting devices that delineate road edges and centrelines. Embedded in the road surface, they are an electronic improvement on the traditional cat's eyes and raised pavement marker in that they may give drivers a larger reaction window.
Road signs in Canada may conform to the Manual of Uniform Traffic Control Devices for Canada (MUTCDC) by the Transportation Association of Canada (TAC) for use by Canadian jurisdictions. Although it serves a similar role to the MUTCD from the US Federal Highway Administration, it has been independently developed and has a number of key differences with its American counterpart, most notably the inclusion of bilingual (English/French) signage for jurisdictions such as New Brunswick with significant anglophone and francophone population, and a heavier reliance on symbols rather than text legends.
Terminology related to road transport—the transport of passengers or goods on paved routes between places—is diverse, with variation between dialects of English. There may also be regional differences within a single country, and some terms differ based on the side of the road traffic drives on. This glossary is an alphabetical listing of road transport terms.
Designs of level crossings, where railway lines cross roads or other paths, vary country-to-country.
Crosswalks in the United States and Canada are normally found at intersections, though sometimes may be found mid-block. Crosswalk installations must follow the regulations specified in the Manual on Uniform Traffic Control Devices (MUTCD). At signalized intersections, crosswalks may have pedestrian signals which display symbols to mandate when pedestrians may cross the street.