A three-way junction (or three-way intersection) is a type of road intersection with three arms. A Y junction (or Y intersection) generally has three arms of equal size coming at an acute or obtuse angle to each other; while a T junction (or T intersection) also has three arms, but one of the arms is generally a smaller road joining a larger road at right angle.
Some three-way junctions are controlled by traffic lights, while others rely upon drivers to obey right-of-way rules, which vary from place to place. In some jurisdictions, chiefly in European countries except the U.K., a driver is always obliged to yield right-of-way for every vehicle oncoming from the right at a junction without traffic signals and priority signs (including T junctions),while in other jurisdictions, chiefly in the U.K. and Australia, a driver turning in a three-way junction must yield for every vehicle approaching the junction (on the way straight ahead) and, if the driver turns right (in left-hand traffic), for every vehicle turning left or (if two vehicles both turn right) for the vehicle approaching from the left (and a road going straight ahead at a three-way junction is normally marked as a priority road). Taiwan (the Republic of China), which has right-hand traffic, has a similar T-junction rule, which, however, is vice verse, obliging a driver turning left to yield for vehicles turning right or (when two drivers both turn left) for the vehicle approaching from the right.
In the People's Republic of China, going straight on red when approaching a T junction on the main road with the intersecting road on the left was permitted until the Road Traffic Safety Law of the People's Republic of China took effect on 1 May 2004.
When one road at a 3-way junction has a higher traffic volume than the other (and particularly when the roads are perpendicular to each other), turns are characterized as "right-in", "right-out", "left-in" and "left-out". A turn "in" represents a turn from the major road into the minor road. A turn "out" represents a turn out of the minor road onto the major road. A 3-way junction allowing all four of these turns is characterized as "full-movement". These terms also apply to turns between roads and driveways.
An experiment was done[ by whom? ][ when? ] in Illinois, United States to allow going straight on red (like a right turn on red) when approaching a T junction on the main road, with the intersecting road on the left. It was a failure. However, at some T junctions where the main road includes at least two lanes on the side away from the intersecting road, the farthest (rightmost, in areas where traffic drives to the right) lane is given the right of way to proceed straight through the intersection at all times, denoted by a "green arrow" signal if a traffic light is installed at the intersection.
In such cases, often that lane is also specially delimited with pavement markings or other lane separation devices, to keep left-turning traffic on the intersecting road from colliding with traffic proceeding through the intersection on the main road. There are now safer variations of this, called continuous green-T (or seagull) intersections , that have a left turn lane off the main road either channelized or otherwise separated from traffic going straight, which allows for a traffic signal on only one side of the road.
Traffic comprises pedestrians, vehicles, ridden or herded animals, trains, and other conveyances that use public ways (roads) for travel and transportation.
A roundabout is a type of circular intersection or junction in which road traffic is permitted to flow in one direction around a central island, and priority is typically given to traffic already in the junction.
An intersection or an at-grade junction is a junction where two or more roads converge, diverge, meet or cross at the same height, as opposed to an interchange, which uses bridges or tunnels to separate different roads. Major intersections are often delineated by gores and may be classified by road segments, traffic controls and lane design.
Traffic lights, traffic signals or stoplights – known also as robots in South Africa are signalling devices positioned at road intersections, pedestrian crossings, and other locations in order to control flows of traffic.
A jughandle is a type of ramp or slip road that changes the way traffic turns left at an at-grade intersection. Instead of a standard left turn being made from the left lane, left-turning traffic uses a ramp on the right side of the road. In a standard forward jughandle or near-side jughandle, the ramp leaves before the intersection, and left-turning traffic turns left off of it rather than the through road. Right turns are also made using this type of jughandle. In a reverse jughandle or far-side jughandle, the ramp leaves after the intersection, and left-turning traffic loops around to the right and merges with the crossroad before the intersection.
A hook turn or two-stage turn, also known as a Copenhagen Left, is a road cycling manoeuvre or a motor vehicle traffic-control mechanism in which vehicles that would normally turn from the innermost lane of an intersection instead turn from the outermost lane, across all other lanes of traffic.
A superstreet, also known as a restricted crossing U-turn (RCUT), J-turn, or reduced conflict intersection (RCI), is a type of road intersection that is a variation of the Michigan left. In this configuration, in contrast to the Michigan left, traffic on the minor road is not permitted to proceed straight across the major road or highway. Drivers on the minor road wishing to turn left or go straight must turn right onto the major road, then, a short distance away, queue (wait) into a designated U-turn lane in the median. When traffic clears, they complete the U-turn and then either go straight or make a right turn when they intersect the other half of the minor road.
Vehicular cycling is the practice of riding bicycles on roads in a manner that is in accordance with the principles for driving in traffic, and in a way that places responsibility for safety on the individual.
A turn on red is a principle of law permitting vehicles at a traffic light showing a red signal to turn into the direction of traffic nearer to them when the way is clear, without having to wait for a green signal. North American traffic engineers first introduced this rule as a fuel savings measure.
In traffic engineering, there are regional and national variations in traffic light operation. This may be in the standard traffic light sequence or by the use of special signals.
Priority to the right is a right-of-way system, in which the driver of a vehicle is required to give way to vehicles approaching from the right at intersections. The system is stipulated in Article 18.4.a of the Vienna Convention on Road Traffic for countries where traffic keeps to the right and applies to all situations where it is not overridden by priority signs, including side roads and roundabouts.
Iceland never ratified the Vienna Convention on Road Signs and Signals, but road signs in Iceland conform to the general pattern of those used in most other European countries, with certain design elements borrowed from Danish and Swedish practice. Signs tend to be more sparsely employed than in other European countries, especially in rural areas.
An all-way stop – also known as a four-way stop – is a traffic management system which requires vehicles on all the approaches to a road intersection to stop at the intersection before proceeding through it. Designed for use at low traffic-volume locations, the arrangement is common in the United States, Canada, Mexico, South Africa, and Liberia, as well as in a number of, usually rural, locations in Australia where visibility on the junction approaches is particularly poor. The stop signs at such intersections may be supplemented with additional plates stating the number of approaches.
A seagull intersection or continuous green T-intersection is a type of three-way road intersection, usually used on high traffic volume roads and dual carriageways. This form of intersection is popular in Australia and New Zealand, and sometimes used in the United States and other countries.
Road signs in Thailand are standardized road signs similar to those used in other nations but with certain differences. Until the early 1980s, Thailand closely followed UK, Australian, and Japanese practices in road sign design, with diamond-shaped warning signs and circular restrictive signs to regulate traffic. Signs usually use the FHWA Series fonts typeface also used in the United Kingdom.
The design of road signs in Poland is regulated by Regulation of the Ministers of Infrastructure and Interior Affairs and Administration on road signs and signals. The Annex 1 to the regulation describes conditions related to usage of the road signs – size, visibility, colors and light reflections, typeface and text, criteria of choosing the type of foil to signs faces, colorful specimens and schematics.
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.
Bosnia and Herzegovina is a signatory of Vienna Convention on Road Signs and Signals. Therefore, road signs do not differ much from the rest of Europe. Ministry of Transportation of Bosnia and Herzegovina regulates them.
Road signs in Cambodia are standardized road signs similar to those used in other nations but with certain differences.
These road signs are used in Vietnam following Chinese and French practice. Some signs are written in both Vietnamese and English. The signs are prescribed by the Ministry of Transportation of Vietnam.