Lane
A lane is the area of a street or road marked by white or yellow lines, in which motorists maintain a consistent direction of travel. Most countries with a significant number of automobiles maintain lanes on their roads, and strictly enforce laws requiring drivers to stay in their lanes as much as possible (as opposed to randomly "drifting" or "weaving" which is common in lane-less countries like Egypt).
Types of lanes
- A through lane or traffic lane is the default type of lane for through traffic. At intersections, these may be indicated by arrows on the pavement pointing straight ahead.
- A fire lane is the area next to a curb, which is reserved for firefighting equipment in the event of a fire. Parking in these areas, usually marked by red lines, often warrants a parking ticket.
- A loading lane is an area next to a curb, which is reserved for loading and unloading passengers. It may be marked by a "LOADING ONLY" sign or a yellow or white curb.
- A passing lane is often provided on steep mountain grades, in order to allow smaller vehicles to pass larger, slower ones. This is sometimes called a climbing lane if on the uphill side. Passing lanes may also be provided on long stretches of other roadway. On two-lane roads, passing in the lane of oncoming traffic is sometimes allowed given a long enough straightaway, if the broken line is on the normal side of travel.
- An auxiliary lane along a highway or motorway connects slip roads, with the entrance ramp or acceleration lane from one interchange leading to the exit ramp or deceleration lane of the next.
- The emergency lane of a road (also known as the breakdown lane or shoulder) is reserved for breakdowns, and for emergency vehicles. Often, especially in rural areas, these lanes deliberately have ruts cut in them, in order to warn drivers that they are leaving the roadway. This feature is especially important in the circumstance that a driver falls asleep at the wheel.
- An HOV lane or carpool lane is reserved for carpooling. It 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 turn lane is set aside for slowing down and making a turn, so as not to disrupt traffic. At a full intersection with a traffic light, turn lanes are used more to hold traffic until the light changes.
- A bike lane is a half-lane reserved for bicycling. This may be indicated by a bicycle icon, the word "BIKE" (or its local equivalent), or both.
- A bus lane is reserved for buses, especially if there is an overhead catenary for electric buses.
- A reversible lane is one which uses overhead lights, signs, poles or barriers to indicate the current direction of travel it is to be used for. Typically, it is used at rush hour to accommodate extra traffic, and at other times as a center turn lane. In between, there is approximately one hour where no traffic is allowed. While the idea is very simple, the suicide lane became a slang word for this, because many people did not pay attention to their driving or the lights. Because of their history of numerous accidents and collisions, reversible lanes are rarely used now. However, there are some functional examples on the river bridges just east of downtown Los Angeles which use lights only and nothing else to indicate the direction of traffic for each lane. Some places, like Hawaii, call these lanes contraflow lanes and enforce them with plastic poles which are manually rearranged by work crews before and after rush hour.
Lane markings
In general, broken lines mean passing is allowed, single solid lines mean it is discouraged, and double solid lines mean it is prohibited, as it often is in tunnels.
In most countries, yellow is used down the center to denote oncoming traffic is across the line or on a dual carriageway a median (central reservation) segregates the traffic. White is usually used to separate traffic going in the same direction; but some places have this reversed.
Some Western European countries reserve white for routine lane markings of any kind, and use yellow to indicate when lanes are being shifted temporarily to make room for construction projects. New Zealand uses a dashed white line to indicate when passing against opposing traffic is allowed on two-lane roads and to separate lanes going in the same direction, with chaotic results.
In all countries, private roads and parking lots often ignore the rules altogether.
In the U.K., zig-zag lines painted on the street mark a pedestrian crossing area. In the U.S., such areas (crosswalks) are indicated at a minimum by a pair of white lines. On major boulevards, crosswalks are further highlighted by zebra stripes, which are large white rectangles in the crosswalk perpendicular to traffic.
"Neutral" areas where traffic is prohibited are often painted with stripes. These areas are often called the gore or gore point where they are formed by the merging or separation of lanes.
Lines are usually painted with highly reflective paint, often with tiny clear beads that reflect light straight back like a raindrop. Glass and now plastic reflectors are often embedded next to the lines for improved nighttime visibility. In California and Nevada, the reflectors are the lines, and no paint is used (except for certain freeways built from white concrete where painted stripes are added to make the lanes more visible through sun glare). Frequently, the "back" of the white reflectors are red, to indicate the wrong direction of travel for anyone who enters the wrong way.
In California, the white round ceramic button reflectors used to mark lanes on most freeways are known as Botts dots, after Eugene Botts, the Caltrans engineer who invented the epoxy that keeps them glued down. California cities also use Botts dots on major arterials; the big exception is the City of Los Angeles, which cannot afford to maintain Botts dots or any raised reflectors due to its fiscal problems and uses only paint.
See also: Lane departure warning system.