Terminology related to road transport—the transport of passengers or goods on paved (or otherwise improved) 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.
A specific category of three-lane road, consisting of two lanes in one direction and one lane in the other, alternating every few kilometres, and separated usually with a steel cable barrier.
A specific category of one-lane road being built in Denmark and Sweden, consisting of a single two-way lane with extra wide shoulders for pedestrians and cyclists.
A transportation and traffic informationtelephone hotline in some regions of the United States and Canada that was initially designated for road weather information.
A method of collecting tolls on highways using toll barriers at regularly spaced intervals on the toll road's mainline, usually charging a flat rate at each barrier.
A roadtraffic control measure designed to prevent congestion and gridlock at junctions. The surface of the junction is typically marked with a criss-cross grid of diagonal painted lines (or only two lines crossing each other in the box), and vehicles may not enter the area so marked unless their exit from the junction is clear (or, if turning, to await a gap in the oncoming traffic flow).
A past physical design of road signs in the United States in which retroreflective buttons made of transparent plastic are placed in rows following the contours of sign legend elements, usually painted white, such as letters, numbers, arrows, and borders.
An auxiliary route that relieves congestion along the mainline by routing traffic around a city or congested area. Can also be used to refer to a segment of road built to reroute the mainline away from a city or congested area.
A width of road on which a vehicle is not restricted by any physical barriers or separation to move laterally. A roadway can comprise one or more carriageways; single carriageways may contain both directions of traffic for the roadway, while multiple carriageways can separate traffic by direction or type.
A two-level interchange in which turns are handled by eight total ramp or slip roads, four of which form loops that give the interchange the shape of a cloverleaf from the air. Each ramp allows traffic from one direction of a roadway to access only one direction of the crossroad: e.g. from northbound to eastbound while a separate ramp connects from northbound to westbound. Traffic is fully grade separated; it does not need to stop to make any of the connections between the two roadways.
An intersection where vehicles attempting to turn across the opposing direction of traffic (left in right-hand drive jurisdictions; right in left-hand drive jurisdictions) cross before they enter the intersection. No left turn signal in the intersection is then necessary.
A former highway which was removed from the highway system is said to be decommissioned. The term also applies to a designation which was removed from a highway system, such as when the U.S. Route 66 was removed from the United States Numbered Highway System in 1985. The physical roadbed typically remains usable, and it may then receive a different designation as another classification of road.[1][2]
Road signage that is built by attaching mass-produced sheet-metal characters (and graphics, such as route shields and arrows) to the sign face, through means such as screws or rivets.
An interchange between a freeway and a minor road where the off-ramp diverges only slightly from the freeway and runs directly across the minor road at an at-grade intersection, becoming an on-ramp that returns to the freeway in similar fashion.
A type of diamond interchange in which the two directions of traffic on the non-freeway road cross to the opposite side on both sides of the bridge at the freeway.
Regulations that govern the activities of commercial truck drivers, most notably limiting the number of hours a person may drive during the day or week.
A system of toll collection where a driver attaches a transponder to his or her vehicle or where a camera recognizes the vehicle registration plates. Tolls are charged automatically to the driver, either by prepaid account or by regular billing, when the vehicle passes through a toll booth or gantry.
A flood plain crossing built at or close to the natural ground level,[3] designed to be submerged under water, but withstand such conditions—typically used when flood frequency or time span is minimal, traffic volumes are low, and the cost of a bridge is uneconomic.[4]
The method of aligning a junction of two or more road axes at different heights (grades) so that they will not disrupt the traffic flow on other transit routes when they cross each other.
A form of traffic congestion where "continuous queues of vehicles block an entire network of intersecting streets, bringing traffic in all directions to a complete standstill".[5]
Hairpin turn, hairpin bend, hairpin corner, or hairpin curve
A bend in a road with a very acute inner angle that resembles a hairpin/bobby pin, making it necessary for an oncoming vehicle to turn almost 180° to continue on the road.
An altered mental state in which a person can drive a car, truck or other automobile great distances, responding to external events in the expected, safe and correct manner with no recollection of having consciously done so.
A road junction that typically uses grade separation, and one or more ramps, to permit traffic on at least one highway to pass through the junction without directly crossing any other traffic stream.
A type of ramp or slip road where 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 countries that drive on the right).
Part of a carriageway or roadway that is designated for use by a single line of vehicles, to control and guide drivers and reduce traffic conflicts.[6]
Riding a bicycle or motorcycle between lanes or rows of slow moving or stopped traffic moving in the same direction.
Legislative route
A highway defined by laws passed in a legislature. The numbering of such highways may or may not correspond to the numbers familiar to the posted route number.
An arrangement of roadways within a major highway where long distance traffic can use lanes with fewer interchanges compared to local traffic which use 'local' or 'collector' lanes that have access to all interchanges.
A manual published by the Federal Highway Administration in the United States, or similar manuals published by state departments of transportation, that specifies the standards for traffic signs, highway markings, and traffic signals (collectively "traffic control devices"). The manual includes specifications on typefaces, colors, and shapes of signs, as well as placement of these traffic control devices.
The reserved area that separates opposing lanes of traffic on divided roadways. The reserved area may simply be paved or grass, but can be adapted to other functions, such as decorative landscaping, trees, a median barrier, or railway or streetcar lines.
A law which requires motorists to move over and change lanes to give safe clearance to law enforcement officers, firefighters, ambulances, utility workers, and in some cases, tow-truck drivers.
A broad, landscaped highwaythoroughfare, particularly a roadway in a park or connecting to a park from which trucks and other heavy vehicles are often excluded.[8]
An interchange that has loop ramps, as in a cloverleaf, but does not have the full set of eight ramps. These use between four and seven ramps and are not full grade-separated; traffic making certain movements between the intersecting roadways must stop.
Public transport, public transportation, public transit, mass transit, or transit
A system of transport for passengers by group travel systems available for use by the general public, typically managed on a schedule and operated on established routes.
An intersection between two roads with an additional "quadrant roadway" between two legs of the intersecting roads. Left turns (in right-hand traffic countries) or right turns (in left-hand traffic countries) are made via the quadrant roadway rather than at the main intersection.
A road surface marker used on roads, usually made with plastic, ceramic, thermoplastic paint or occasionally metal, and come in a variety of shapes and colors.
Rest area, travel plaza, rest stop, or service area
A public facility, located next to a large thoroughfare such as a highway, expressway, or freeway at which drivers and passengers can rest, eat, or refuel without exiting on to secondary roads.
Restricted crossing U-turn (RCUT) or reduced conflict intersection
A lane in which traffic may travel in either direction, depending on certain conditions. Typically, it is meant to improve traffic flow during rush hours, by having overhead traffic lights and lighted street signs notify drivers which lanes are open or closed to driving or turning.
Ridesharing company, transportation network company, or mobility service provider
A company that matches passengers with vehicles, via websites and mobile apps.
A type of easement granted or reserved over the land for transportation purposes, this can be for a highway, public footpath, rail transport, canal, as well as electrical transmission lines, oil and gas pipelines.[9]
Ring road, beltway, circumferential highway, or orbital
A highway or series of highways that encircle a city or town.
A thoroughfare, route, or way on land between two places that has been paved or otherwise improved to allow travel by foot or some form of conveyance, including a motor vehicle, cart, bicycle, or horse.
Road diet, lane reduction, or road rechannelization
A technique in transportation planning whereby the number of travel lanes and/or effective width of the road is reduced in order to achieve systemic improvements.
Direct charges levied for the use of roads, including road tolls, distance or time based fees, congestion charges and charges designed to discourage use of certain classes of vehicle, fuel sources, or more polluting vehicles.
Mechanical (cat's-eye reflectors), non-mechanical (paint), or temporary devices used on a road surface that convey information to motorists, most commonly to delineate traffic lanes or to promote road safety.
A combination of letters and/or numbers that serve to identify a particular road. Route numbers may be assigned randomly or as part of a regional numbering scheme.
Rumble strips, sleeper lines, rumple strips, audible lines, the corduroy, or growlers
A road surface mark used to alert inattentive drivers of potential danger, by causing a tactilevibration and audible rumbling transmitted through the wheels into the vehicle interior.
Runaway truck ramp, runaway truck lane, escape lane, emergency escape ramp or truck arrester bed
An emergency lane with a sand or gravel-filled bed large enough to accommodate and safely stop large trucks, usually adjacent to a road with a steep down-hill grade.
Seagull intersection, continuous green T-intersection, turbo-T, or high-T intersection
A type of three-way road intersection, usually used on high traffic volume roads and dual carriageways. In this type of intersection, one direction of traffic travels straight through without stopping while those wishing to turn onto the side road at the intersection simply bear into a separate lane, which forms one "wing" of the seagull. Here, they meet the opposite carriageway and the side road. Traffic wishing to turn out of the side road, simply cross the intersecting carriageway and drive up the other "wing" of the seagull, and merge onto the other carriageway.
A nickname sometimes given to a complicated or massively intertwined road traffic interchange that resembles a plate of spaghetti. The term was originally used to refer to the Gravelly Hill Interchange on the M6 in Birmingham.[11]
A free-flowing, grade-separatedjunction between two roads, where movements are handled by semi-directional flyovers or under ramps. Vehicles first exit the main carriageway, then complete the turn via a ramp that crosses both highways, eventually merging with the traffic from the opposite side of the interchange.
State highway, state road, state route, provincial highway, provincial road, or provincial route
Superstreet, restricted crossing U-turn (RCUT), J-turn, or reduced conflict intersection
An at-grade intersection where traffic on the minor road cannot go straight across. Traffic on the minor road wishing to turn left or continue straight must turn right onto the major road, then, a short distance away, use a U-turn (or crossover) lane in the median before either going straight or making a right turn when they intersect the other half of the minor road.
Super two, super two-lane highway, or wide two lane
When a driver drives behind another vehicle while not leaving sufficient distance to stop without causing a collision if the vehicle in front stops suddenly.
A lane allowing cars traveling on one side of a one-way frontage road to U-turn onto the opposite frontage road (typically crossing over or under a freeway or expressway).
A method of turning a vehicle around (making a 180° turn) in close quarters, such as in the middle of a road at a point other than an intersection.
Three-way junction, 3-way junction, 3-way intersection, Y junction, Y intersection, T junction, or T intersection
a type of road intersection with three arms. A Y junction generally has 3 arms of equal size. A T junction also has 3 arms, but one of the arms is generally a minor road connecting to larger road.
Thru traffic
Road users passing through an area whose destination is elsewhere.
A toll road where motorists pay a toll rate based on the distance traveled from their origin to their destination exit. Motorists take a ticket when entering the road and pay the toll and surrender the ticket upon exiting.
A method of conveying information to people who are using a road. Depending on location, the main color of the sign can tell the motorist what type of information is presented on the sign.
A type of junction that allows traffic traveling in one direction on a road to efficiently make a U-turn typically without backing up or making dangerous maneuvers in the middle of the traffic stream.
Turn off to stay on (TOTSO)
When a motorist must exit a highway to continue traveling on the same numbered route.
A principle of law permitting vehicles at a traffic light showing a red signal to turn into the direction of traffic nearer to them (almost always after a complete stop) when the way is clear, without having to wait for a green signal.
A highway that has been assigned a route number, but does not bear road markings that would conventionally be used to identify the route with that number.
A traffic sign that can display important messages about special events to motorists. Commute times, weather alerts, AMBER alerts, and advanced notices of road construction or accidents are common messages.
A multilateral treaty designed to increase road safety and aid international road traffic by standardizing the signing system for road traffic (road signs, traffic lights and road markings) in use internationally.
An international treaty designed to facilitate international road traffic and to increase road safety by establishing standard traffic rules among the contracting parties.
Weave
Weaving typically occurs at interchanges. Cloverleaf interchanges are especially prone to weaving when an entering vehicle tries to merge into a traffic lane while another vehicle is attempting to exit from the same lane. Weaving also occurs when vehicles enter traffic from inner lanes and must quickly exit from outer lanes.
A concurrency between two roads with opposite signed directions, e.g. a westbound highway and an eastbound highway. Often, the physical roadbed is actually headed in a totally different cardinal direction.
Cooper, Scott (February 14, 2000). "Overview of UCSB's Relationship to the Goleta Old Town Revitalization Plan". University of California, Santa Barbara. Archived from the original on May 23, 2008. Retrieved March 18, 2008. [C]hanges to Highway 217 were now imminent, both because the state bill had been signed which would decommission Highway 217 and transfer its authority to Santa Barbara County—decommissioning of a road in this source broadly signifies the process of removal of state status and transfer to local authority control and management.
Edmonds, Leigh (1997). The Vital Link: A History of Main Roads Western Australia 1926–1996. Nedlands, Western Australia: University of Western Australia Press. p.184. ISBN1-875560-87-4.
MRWA Waterways Section; BG&E Pty Ltd (April 24, 2006). "Floodway Design Guide"(PDF). Main Roads Western Australia. p.4. Archived(PDF) from the original on April 15, 2015. Retrieved April 15, 2015. "Archived copy"(PDF). Archived from the original(PDF) on April 15, 2015. Retrieved April 15, 2015.{{cite web}}: CS1 maint: archived copy as title (link)