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.
0–9 2+1 road 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. 2-1 road 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. 2+2 road A specific type of dual carriageway being built in Ireland, Sweden, and Finland, consisting of two lanes in each direction separated by a steel cable barrier. 3-way junction or 3-way intersection
5-1-1 A transportation and traffic information telephone hotline in some regions of the United States and Canada that was initially designated for road weather information.
A Access road
Advisory speed limit A speed recommendation by a governing body. All-way stop or four-way stop An intersection system where traffic approaching it from all directions is required to stop before proceeding through the intersection. Alternate route or optional route A highway that splits off the mainline and reconnects some distance later. Ambulance A medically equipped vehicle which transports patients to treatment facilities, such as hospitals. Annual average daily traffic (AADT) A measure of total volume of vehicle traffic on a segment of road for a year divided by 365 days to produce an average. Arterial road or arterial thoroughfare A high-capacity urban road designed to deliver traffic at the highest possible level of service. At-grade intersection A junction at which two or more roads cross at the same level or grade. Automobile
Automotive vehicle
Autonomous vehicle
Auxiliary route A highway that supplements a major or mainline highway.
B Backroad A secondary type of road usually found in rural areas. Barrier toll system or open toll system 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. Beltway
Bicycle, bike, or cycle A human-powered or motor-powered, pedal-driven, single-track vehicle, having two wheels attached to a frame, one behind the other. Bicycle boulevard A street that allows local vehicle traffic, but is prioritized for bicycles and other non-motorized travel. Bike freeway, cycling superhighway, fast cycle route, or bicycle highway An informal name for a bicycle path that is meant for long-distance traffic. Bike lane or cycle lane A lane restricted to bicycles. Boom barrier or boom gate A bar or pole pivoted to block vehicular or pedestrian access through a controlled point. Bottleneck
Botts' dots Round non-reflective raised pavement markers used to mark lanes on roads. Boulevard A type of large road, usually running through a city. Box junction A road traffic 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). Broken U-turn
Bus A road vehicle designed to carry many passengers. Bus lane A lane restricted to buses, and sometimes certain other vehicles such as taxis. Bus rapid transit, BRT, busway, or transitway A bus-based public transport system designed to improve capacity and reliability relative to a conventional bus system. Bus station or bus depot A structure where city or intercity buses stop to pick up and drop off passengers. Bus stop A designated place where buses stop for passengers to board or alight from it. Business route or city route An auxiliary route that passes through the central business district of a city. Butterfly junction
Button copy 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. Bypass 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.
C Cab
Cant or camber The gradient of the road surface at 90° to the direction of travel; the difference in height between the edge and the crown of the road. Car or automobile A wheeled motor vehicle used for transportation. Car crash or car accident
Carriageway or roadway 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. Cashless tolling
Cat's eye A retroreflective safety device used in road marking and the first of a range of raised pavement markers. Central reservation
Circumferential highway
City route
Clean vehicle
Climbing lane A lane that allows slower travel for large vehicles, such as large trucks or semi-trailer trucks, ascending a steep grade. Closed toll collection system
Cloverleaf interchange or cloverleaf junction 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. Coastal evacuation route
Collector–distributor lanes
Collector road or distributor road A low-to-moderate-capacity road which serves to move traffic from local streets to arterial roads. Commercial vehicle A motor vehicle used for transporting goods or paying passengers. Concurrency An instance of one physical road bearing two or more different highway, motorway, or other route numbers. Cone
Confirming marker
Congestion
Congestion pricing A system of surcharging users of roads that are subject to congestion. Connector or cutoff An auxiliary route that provides a shortcut between two routes or a connection between two routes that otherwise do no connect. Constitutional route A highway defined in the constitution of the place in which it is located. Only found in Minnesota. Construction area, construction zone, work area, or work zone A stretch of road on which road construction is taking place. Continuous-flow intersection, CFI, crossover displaced left-turn, XDL, or DLT 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. Continuous footway
Continuous green T-intersection
Continuous pavement
Contraflow lane reversal The reversal of direction of traffic in a lane, to facilitate emergency evacuations, roadworks, or events. Control city A city or location posted on a series of traffic signs along a particular stretch of road indicating destinations on that route. Controlled-access highway, motorway, or freeway A type of highway which has been designed for high-speed vehicular traffic, with all traffic flow and ingress/egress regulated. Copenhagen crossing
The corduroy
Country lane A narrow road in the countryside. County highway, county road, or county route A road in the United States and in the Canadian province of Ontario that is designated and/or maintained by the county highway department. Couplet
Crossbuck A traffic sign used to indicate a level railway crossing. Crossing guard, lollipop man/lady, crosswalk attendant or school road patrol A person who temporarily stops vehicular traffic to allow pedestrians to cross the road. Crossroad
Crosswalk
Cul-de-sac, dead end, closed, no through road, no exit, court, or no outlet A street with only one inlet/outlet. Curb or kerb Raised pavement situated along the edge of a roadway. Cycle lane
Cycling superhighway
Cyclist A bicycle rider.
D Dead end
Decommissioned highway 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. Demountable copy 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. Detour A route taking traffic around an area of prohibited or reduced access, such as a construction site.
Diamond interchange 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. Directional interchange
Distributor road
Diverging diamond interchange, DDI, double crossover diamond interchange, or DCD 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. DLT
Drawbridge
Driverless car
Driver's license or driving licence An official document permitting a specific individual to operate a vehicle. Drivers' working hours 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. Driveway or drive A type of private road for local access to one or a small group of structures, and is owned and maintained by an individual or group. Driving under the influence or DUI Operating a vehicle while being impaired by alcohol or other drugs. Dual carriageway or divided highway A class of highway with two carriageways for traffic traveling in opposite directions separated by a median strip or central reservation. Dynamic message sign
E Electronic toll collection 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. Elevated highway A controlled-access highway that is raised above grade for its entire length. Emergency vehicle A vehicle that is designated and authorized to respond to an emergency in a life-threatening situation. Escape lane or emergency escape ramp
Evacuation route
Exit number A number assigned to a road junction, usually an exit from a freeway. Expressway
F Farm-to-market road, ranch-to-market road, farm road, or ranch road A highway that connects rural or agricultural areas to market towns. Fast cycle route
Fire engine, fire truck, or fire lorry A road vehicle (usually a truck) that functions as a firefighting apparatus. Flagger or flagman
Freeway
Frontage road, access road, service road, or parallel road A local road running parallel to a higher-speed, limited-access road.
Floodway