Speed limits on road traffic, as used in most countries, set the legal maximum speed at which vehicles may travel on a given stretch of road. Speed limits are generally indicated on a traffic sign reflecting the maximum permitted speed, expressed as kilometres per hour (km/h) or miles per hour (mph) or both. Speed limits are commonly set by the legislative bodies of national or provincial governments and enforced by national or regional police and judicial authorities. Speed limits may also be variable, or in some places nonexistent, such as on most of the Autobahnen in Germany.
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 and Namibia – are signaling devices positioned at road intersections, pedestrian crossings, and other locations in order to control the flow of traffic.
Traffic calming uses physical design and other measures to improve safety for motorists, car drivers, pedestrians and cyclists. It has become a tool to combat speeding and other unsafe behaviours of drivers. It aims to encourage safer, more responsible driving and potentially reduce traffic flow. Urban planners and traffic engineers have many strategies for traffic calming, including narrowed roads and speed humps. Such measures are common in Australia and Europe, but less so in North America. Traffic calming is a calque of the German word Verkehrsberuhigung – the term's first published use in English was in 1985 by Carmen Hass-Klau.
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.
Speed bumps are a class of traffic calming devices that use vertical deflection to slow motor-vehicle traffic in order to improve safety conditions. Variations include the speed hump, speed cushion, and speed table.
The Manual on Uniform Traffic Control Devices for Streets and Highways is a document issued by the Federal Highway Administration (FHWA) of the United States Department of Transportation (USDOT) to specify the standards by which traffic signs, road surface markings, and signals are designed, installed, and used. In the United States, all traffic control devices must legally conform to these standards. The manual is used by state and local agencies as well as private construction firms to ensure that the traffic control devices they use conform to the national standard. While some state agencies have developed their own sets of standards, including their own MUTCDs, these must substantially conform to the federal MUTCD.
In the United States, speed limits are set by each state or territory. States have also allowed counties and municipalities to enact typically lower limits. Highway speed limits can range from an urban low of 25 mph (40 km/h) to a rural high of 85 mph (137 km/h). Speed limits are typically posted in increments of five miles per hour (8 km/h). Some states have lower limits for trucks, some also have night and/or minimum speed limits.
For driving in the United States, each state and territory has its own traffic code or rules of the road, although most of the rules of the road are similar for the purpose of uniformity, given that all states grant reciprocal driving privileges to each other's licensed drivers. There is also a "Uniform Vehicle Code" which was proposed by a private, non-profit group, based upon input by its members. The UVC was not adopted in its entirety by any state. As with uniform acts in general, some states adopted selected sections as written or with modifications, while others created their own sui generis statutes touching upon the same subject matter. As required by the federal Highway Safety Act of 1966, all states and territories have adopted substantially similar standards for the vast majority of signs, signals, and road surface markings, based upon the Manual on Uniform Traffic Control Devices from the U.S. Department of Transportation. Many of the standard rules of the road involve consistent interpretation of the standard signs, signals, and markings such as what to do when approaching a stop sign, or the driving requirements imposed by a double yellow line on the street or highway. In order to implement their own traffic laws on the property of their own facilities, several federal agencies have also developed their own traffic laws.
Active traffic management is a method of increasing peak capacity and smoothing traffic flows on busy major highways. Techniques include variable speed limits, hard-shoulder running and ramp-metering controlled by overhead variable message signs. It has been implemented in several countries, including Germany, the United Kingdom, Canada and the United States.
An advisory speed limit is a speed recommendation by a governing body, used when it may be non-obvious to the driver that the safe speed is below the legal speed. It is a posting which either approximates the Basic Speed Law or rule or is based on a maximum g-force exerted at a specific speed. Advisory speed limits are often set in areas with many pedestrians, such as in city centres and outside schools, and on difficult stretches of roads, such as on tight corners or through roadworks. While travelling above the advisory speed limit is not illegal per se, it may be negligence per se and liability for any collisions that occur as a result of traveling above the limit can be placed partially or entirely on the person exceeding the advisory speed limit.
A HAWK beacon is a traffic control device used to stop road traffic and allow pedestrians to cross safely. It is officially known as a pedestrian hybrid beacon. The purpose of a HAWK beacon is to allow protected pedestrian crossings, stopping vehicular traffic only as needed. The HAWK beacon is a type of traffic control alternative to traffic control signals and/or where an intersection does not meet traffic signal warrants.
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).
Road speed limits in the United Kingdom are used to define the maximum legal speed for vehicles using public roads in the UK.
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.
Road signs used by countries in the Americas are significantly influenced by the Manual on Uniform Traffic Control Devices (MUTCD), first released in 1935, reflecting the influence of the United States throughout the region. Other non-American countries using road signs similar to the MUTCD include Australia, Indonesia, Ireland, Japan, Malaysia, New Zealand, and Thailand. They, along with the US Virgin Islands, are also the only countries listed here which drive on the left—with the exception of Liberia and the Philippines, both of which drive on the right.
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.
The Ohio Manual of Uniform Traffic Control Devices is the standard for traffic signs, road surface markings, and traffic signals in the U.S. state of Ohio. It is developed by the Ohio Department of Transportation's Office of Roadway Engineering "in substantial conformance to" the national Manual on Uniform Traffic Control Devices developed by the Federal Highway Administration. The first edition of the OMUTCD was published in 1924; the most recent edition was published in 2012. Ohio is one of ten states that publish their own editions of the MUTCD.
The California Manual on Uniform Traffic Control Devices is the standard for traffic signs, road surface markings, and traffic signals in the U.S. state of California. It is developed by the California Department of Transportation (Caltrans) Division of Safety Programs "in substantial conformance to" the national Manual on Uniform Traffic Control Devices developed by the Federal Highway Administration. The first edition of the CA MUTCD was published in 2006, replacing an earlier supplement to the national MUTCD. The most recent edition was published in 2014, incorporating the 2009 edition of the national MUTCD. California is one of ten states that publish their own editions of the MUTCD. The CA MUTCD defines the content and placement of traffic signs. Design specifications are detailed on a section of the Caltrans website that is based on the national Standard Highway Signs and Markings (SHSM) document.
Road signs in Puerto Rico are regulated in the Manual de Rotulación para las Vías Públicas de Puerto Rico, Puerto Rico’s supplement to the Manual on Uniform Traffic Control Devices (MUTCD), the standard for road signs, signals, and markings in the United States. It is developed by the Puerto Rico Highways and Transportation Authority (PRHTA) "in substantial conformance to" the national MUTCD developed by the Federal Highway Administration.
