Lane driving
In the context of traffic control, a lane is part of a  carriageway (roadway) that is designated for use by a single line of vehicles, to control and guide drivers and reduce traffic conflicts. Most public roads (highways) have at least two lanes, one for traffic in each direction, separated by  lane markings. On multilane roadways and busier two-lane roads, lanes are designated with  road surface markings. Major highways often have two multi-lane roadways separated by a  median.
Some roads and bridges that carry very low volumes of traffic are less than 15 feet (4.6 m) wide, and are only a single lane wide. Vehicles travelling in opposite directions must slow or stop to pass each other. In rural areas, these are often called  country lanes. In urban areas,  alleys are often only one lane wide. Urban and suburban one lane roads are often designated for  one-way traffic.

Types of lane

A traffic lane or travel lane is a lane for the movement of vehicles traveling from one destination to another, not including shoulders.

A through lane or thru lane is a traffic lane for through traffic. At intersections, these may be indicated by arrows on the pavement pointing straight ahead.

An express lane of a road is used for faster moving traffic and has less access to exits/off ramps. In other areas, an express lane may refer to a HOV lane (see below).

A reversible lane (contraflow lane) is a lane where the direction of traffic can be changed to match the peak flow. They are used to accommodate periods of high traffic flow, especially rush hour where the flow is predominantly in one direction, on roads that cannot be easily widened such as over bridges. One or more lanes are removed from the opposing flow and added to the peak flow.

An auxiliary lane is a lane other than a through lane, used to separate entering, exiting or turning traffic from the through traffic.

An acceleration lane or merge lane allows traffic entering a highway to accelerate to the speed of through traffic before merging with it.

A deceleration lane is a lane adjacent to the primary road or street used to improve traffic safety by allowing drivers to pull out of the through lane and decelerate safely before turning off a surface street or exiting a freeway.

A turn lane is set aside for slowing down and making a turn, so as not to disrupt traffic. By removing turning traffic from the through lanes, motorist safety is improved and delay is removed, but crossing distances for pedestrians are lengthened, increasing their exposure to collisions.

A two-way center turn lane is a lane in the center of a roadway to allow drivers traveling in either direction to pause before turning across oncoming traffic ( a left turn in right-driving countries, or a right turn in left-driving countries) while waiting for a gap in traffic.

A passing lane is sometimes provided on busy two-lane roads to allow drivers to pass slower vehicles without having to cross the center line and risking a head-on collision.

A climbing lane, truck lane, or crawler lane is often provided on steep mountain grades, in order to allow smaller vehicles to pass larger, slower ones. The lane is marked only on the uphill stretch and usually a short distance afterward (for regaining speed).

An operational lane or auxiliary lane is an extra lane on the entire length of highway between interchanges, giving drivers more time to merge in or out. The lane is created when an entrance ramp meets the highway, and drops out (with an "exit only" sign) to become the ramp at the next exit.

A transfer lane of a road is used to move from express lanes to collector lanes, or vice-versa; it is somewhat similar to an auxiliary lane.
A collector lane of a road is used for slower moving traffic and has more access to exits/off ramps.

Dedicated lanes are traffic lanes set aside for particular types of vehicles.

A high occupancy vehicle or carpool lane is reserved for carpooling. In the US, they may be marked with a diamond icon every few hundred feet (hence the nickname "diamond lane"), or separated from other lanes by double broken white lines, a continuous pair of double yellow lines, or just a single broken white line.

A High-occupancy toll lane is a combination of an HOV lane and toll collection technology that allows drivers without passengers to use the HOV lane by paying a premium price for the privilege

A designated bicycle lane is a portion of the roadway or shoulder designated for the exclusive or preferential use of bicyclists. This designation is indicated by special word and/or symbol markings on the pavement and "BIKE LANE" signs.

A motorcycle lane is provided at certain roads and highways such as the Federal Highway in Malaysia to segregate the motorcycle traffic from the main roadways to reduce motorcycle-related accidents. The motorcycle lane may form a part of the hard shoulder, or may be one or more completely separated lanes.

A bus lane is reserved for buses providing public transportation on a fixed route, sometimes with overhead catenary for trolleybuses. In some countries, bus lanes may also be used by some other traffic, such as taxis, bicycles and motorbikes.

A tram lane is a lane reserved for the use of buses, trams and taxicabs. It is usually encountered in cities with curbside tram network, such as Zagreb.

A truckway is a dedicated lane for longer length trucks; for instance, the Florida Turnpike allows 29.3 meter double trailer combinations, in contrast to normal Florida highways' 16.2 meter limit. Since the major cost of trucking is the fixed cost of the same trailer with its driver the cost per ton of operating with truckway size and weight allowances is 35 to 40 percent below the cost of operations on the non-truckways.

In some areas, the lane adjacent to the curb is reserved for non-moving vehicles.

A parking lane is reserved for parallel parking of vehicles.
A fire lane is the area next to a curb, which is reserved for firefighting equipment, ambulances, or other emergency vehicles. Parking in these areas, often marked by red lines, usually warrants a parking ticket

A loading lane (loading zone in the United States) is an area next to a curb, which is reserved for loading and unloading passengers and/or freight. It may be marked by a sign ("LOADING ONLY" or "LOADING ZONE") or by a yellow or white-painted curb.

A hard shoulder is sometimes called an emergency lane or a breakdown lane, when it is reserved for breakdowns, and for emergency vehicles. On some congested roads, the shoulder is used as a vehicle lane during peak travel hours.

By law or custom, inside lanes are often reserved for faster traffic, and outside lanes are used by slower traffic

An overtaking lane is the lane furthest from the shoulder of a multi-lane carriageway/roadway (sometimes called the fast lane, although this is deprecated by the authorities).

The slow lane is the lane nearest to the shoulder of a multi-lane carriageway/roadway. These usages lead to the phrases life in the slow lane and life in the fast lane, used to describe relaxed or busy lifestyles, respectively and used as the titles of various books and songs.