Shoulder (road)
Encyclopedia
A hard shoulder, or simply shoulder, is a reserved area by the verge of a road
Road
A road is a thoroughfare, route, or way on land between two places, which typically has been paved or otherwise improved to allow travel by some conveyance, including a horse, cart, or motor vehicle. Roads consist of one, or sometimes two, roadways each with one or more lanes and also any...

 or motorway. Generally it is kept clear of motor vehicle traffic. Shoulders have multiple uses, including:
  • In the event of an emergency or breakdown
    Breakdown (vehicle)
    A vehicle breakdown is the operational failure of a motor vehicle in such a way that the underlying problem prevents the vehicle from being operated at all, or impedes the vehicle's operation so much, that it is very difficult or nearly impossible, or dangerous to operate, or else at risk of...

    , a motorist can pull into the hard shoulder to get out of the flow of traffic and obtain an element of safety
  • Shoulders, especially paved or hard shoulders, increase road safety. They allow some extra space should a motorist need to take evasive action or need to recover control of their vehicle before a run-off-road collision
    Run-off-road collision
    A run-off-road collision is a type of single-vehicle accident that occurs when a vehicle leaves the roadway. Contributing factors often include loss of control or mis-judging a curve, or attempting to avoid colliding with another road user or an animal...

     occurs.
  • Emergency vehicle
    Emergency vehicle
    An emergency vehicle is any vehicle that is designated and authorized to respond to an emergency. These vehicles are usually operated by designated agencies, often part of the government, but also run by charities, non-governmental organizations and some commercial companies...

    s such as ambulance
    Ambulance
    An ambulance is a vehicle for transportation of sick or injured people to, from or between places of treatment for an illness or injury, and in some instances will also provide out of hospital medical care to the patient...

    s and police car
    Police car
    A police car is a ground vehicle used by police, to assist with their duties in patrolling and responding to incidents. Typical uses of a police car include transportation for officers to reach the scene of an incident quickly, to transport criminal suspects, or to patrol an area, while providing a...

    s may also use the shoulder to bypass traffic congestion
    Traffic congestion
    Traffic congestion is a condition on road networks that occurs as use increases, and is characterized by slower speeds, longer trip times, and increased vehicular queueing. The most common example is the physical use of roads by vehicles. When traffic demand is great enough that the interaction...

  • Shoulders provide space for bicyclists to ride out of vehicle traffic
  • In areas without sidewalks, pedestrians can walk on shoulders
  • On curbed roadways, shoulders move the gutter away from the travel lanes. This reduces the risk of hydroplaning, and reduces splash and spray of stormwater
    Stormwater
    Stormwater is water that originates during precipitation events. It may also be used to apply to water that originates with snowmelt that enters the stormwater system...

     onto pedestrians using an adjacent sidewalk.
  • Shoulders provide structural support of the roadway
  • Shoulders move water away from the roadway before it can infiltrate into the road's subbase
    Subbase (pavement)
    In highway engineering, subbase is the layer of aggregate material laid on the subgrade, on which the base course layer is located. It may be omitted when there will be only foot traffic on the pavement, but it is necessary for surfaces used by vehicles....

    , increasing the life expectancy of the road surface.

General characteristics

The shoulder is usually slightly narrower than a full traffic lane. In some cases, particularly on old rural roadways, shoulders do not exist or are made of gravel
Gravel
Gravel is composed of unconsolidated rock fragments that have a general particle size range and include size classes from granule- to boulder-sized fragments. Gravel can be sub-categorized into granule and cobble...

 rather than hard asphalt
Asphalt
Asphalt or , also known as bitumen, is a sticky, black and highly viscous liquid or semi-solid that is present in most crude petroleums and in some natural deposits, it is a substance classed as a pitch...

 or concrete
Concrete
Concrete is a composite construction material, composed of cement and other cementitious materials such as fly ash and slag cement, aggregate , water and chemical admixtures.The word concrete comes from the Latin word...

. These are known as soft shoulders in comparison. Because the road surface changes at that point, they are less safe if they need to be used for emergency maneuvers, so modern practice is to build a hard shoulder whenever possible.

To save money, the hard shoulder is sometimes not paved to the same thickness as the through lanes, so if vehicles were to attempt to use it as a through lane regularly, it would rapidly deteriorate. The shoulder also often collects various bits of road debris
Road debris
Road debris, a form of road hazard, is debris on or off a road. Road debris includes substances, materials, and objects that are foreign to the normal roadway environment...

 that can make driving there unsafe.

Drivers will sometimes drift into the shoulder when being overtaken by passing vehicles, particularly on two-lane roads. However, it is extremely unsafe, as well as often illegal, to abuse the hard shoulder by 'undertaking' passing vehicles that are nearer the centre of the road. (Some roads and expressways have a hard shoulder that is of such a narrow width that 'undertaking' is impossible.)

On many roads, the shoulder disappears for short periods, particularly near exits and sometimes when going across or under bridge
Bridge
A bridge is a structure built to span physical obstacles such as a body of water, valley, or road, for the purpose of providing passage over the obstacle...

s where the cost savings outweigh the disadvantages of not having the shoulder. However, some roads have a narrow shoulder for significant distances. This makes it difficult for large vehicles to pull into the hard shoulder altogether.

The Jingjintang Expressway
Jingjintang Expressway
Opened in September 1993, the Jingjintang Expressway , also known as the Jingtang Expressway, links Beijing via central Tianjin to the Tanggu District in eastern Tianjin...

 in northeastern China
China
Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...

 is an example of this phenomenon. Its hard shoulder is 2.4 metres wide, which is not wide enough for some automobiles. As a result, some motorists are unable to fully exit the mainline when they need to pull over, so they end up in a position that is halfway in the rightmost lane and halfway in the hard shoulder. The result is often a traffic jam and occasionally a collision.

Use as bus-only shoulder

In some jurisdictions in the United States and Canada, bus
Bus
A bus is a road vehicle designed to carry passengers. Buses can have a capacity as high as 300 passengers. The most common type of bus is the single-decker bus, with larger loads carried by double-decker buses and articulated buses, and smaller loads carried by midibuses and minibuses; coaches are...

es are allowed to drive on the shoulder to pass traffic jams, which is called a bus-only shoulder or bus-bypass shoulder; the term "bus-only shoulder lane" is incorrect from a technical and legal standpoint. In Ontario
Ontario
Ontario is a province of Canada, located in east-central Canada. It is Canada's most populous province and second largest in total area. It is home to the nation's most populous city, Toronto, and the nation's capital, Ottawa....

, Highway 403
Highway 403 (Ontario)
King's Highway 403, also known as Highway 403, is a 400-series highway in the Canadian province of Ontario that travels between Woodstock and Mississauga, branching off from and reuniting with Highway 401 at both ends and travelling south of it through Hamilton and Mississauga. It is concurrent...

 had its shoulders between Hurontario Street and Erin Mills Parkway widened in 2003 so they serve a dual-purpose as bus lanes and accident lanes; in the Minneapolis-St. Paul region of Minnesota
Minnesota
Minnesota is a U.S. state located in the Midwestern United States. The twelfth largest state of the U.S., it is the twenty-first most populous, with 5.3 million residents. Minnesota was carved out of the eastern half of the Minnesota Territory and admitted to the Union as the thirty-second state...

, over 270 miles of shoulder have been designated for use by buses.

Peak period use by all traffic

On specially signed sections of highway in the Boston Metro Area, cars are allowed to use the shoulder as they would a normal lane during morning and evening rush hours. The same scheme is employed elsewhere, such as on Interstate 66
Interstate 66
Interstate 66 is an Interstate Highway in the eastern United States. As indicated by its even route number, it runs in an east–west direction. Its western terminus is at Middletown, Virginia, at an intersection with Interstate 81; its eastern terminus is in Washington, D.C., at an...

 in Virginia between the Capital Beltway and US-50.

In the UK, usage of the hard shoulder is known as hard shoulder running. A pilot project on an 11-mile stretch of the M42 motorway
M42 motorway
The M42 motorway is a major road in England. The motorway runs north east from Bromsgrove in Worcestershire to just south west of Ashby-de-la-Zouch in Leicestershire, passing Redditch, Solihull, the National Exhibition Centre and Tamworth on the way. The section between the M40 and M6 road forms...

, near Birmingham
Birmingham
Birmingham is a city and metropolitan borough in the West Midlands of England. It is the most populous British city outside the capital London, with a population of 1,036,900 , and lies at the heart of the West Midlands conurbation, the second most populous urban area in the United Kingdom with a...

 began in September 2006. Special signage, new laybys and a variable speed limit
Speed limit
Road speed limits are used in most countries to regulate the speed of road vehicles. Speed limits may define maximum , minimum or no speed limit and are normally indicated using a traffic sign...

 have been put in place to improve safety. This has proved very successful, with journey times decreasing by 26% northbound and 9% southbound. Drivers can also better predict their journey times as the variability decreased by 27%. The average accident rate drop from 5.2 to 1.5 per month It has also proved popular with motorists, 60% of whom want to see it expanded to other English motorways. The system had been expanded to the M6
M6 motorway
The M6 motorway runs from junction 19 of the M1 at the Catthorpe Interchange, near Rugby via Birmingham then heads north, passing Stoke-on-Trent, Manchester, Preston, Carlisle and terminating at the Gretna junction . Here, just short of the Scottish border it becomes the A74 which continues to...

, with plans to implement it to parts of M1
M6 motorway
The M6 motorway runs from junction 19 of the M1 at the Catthorpe Interchange, near Rugby via Birmingham then heads north, passing Stoke-on-Trent, Manchester, Preston, Carlisle and terminating at the Gretna junction . Here, just short of the Scottish border it becomes the A74 which continues to...

, M25
M25 motorway
The M25 motorway, or London Orbital, is a orbital motorway that almost encircles Greater London, England, in the United Kingdom. The motorway was first mooted early in the 20th century. A few sections, based on the now abandoned London Ringways plan, were constructed in the early 1970s and it ...

, M60
M60 motorway
The M60 motorway, or Manchester Orbital, is an orbital motorway circling Greater Manchester, a metropolitan county in North West England. It passes through all Greater Manchester's metropolitan boroughs except for Wigan and Bolton...

 and M62
M62 motorway
The M62 motorway is a west–east trans-Pennine motorway in Northern England, connecting the cities of Liverpool and Hull via Manchester and Leeds. The road also forms part of the unsigned Euroroutes E20 and E22...

 by 2015.

Increased cyclist safety

Direct rear impacts with cyclists are a more prominent collision type in arterial/rural road type situations. When they occur in such circumstances they are also associated with significantly increased risk of fatality. Data collated by the OECD indicates that rural locations account for 35% or more of cycling fatalities in Denmark, Finland, France, Great Britain, Japan, the Netherlands, and Spain.

The use of appropriately designed segregated space on arterial or interurban routes appears to be associated with reductions in overall risk. In Ireland
Ireland
Ireland is an island to the northwest of continental Europe. It is the third-largest island in Europe and the twentieth-largest island on Earth...

, the provision of hard shoulders on interurban routes in the 1970s reportedly resulted in a 50% decrease in accidents. It is reported that the Danes have also found that separate cycle tracks lead to a reduction in rural collisions.

Republic of Ireland

Full-width hard shoulders are provided on most new, upgraded (from the 1980s onwards), and major national roads
Roads in Ireland
The island of Ireland, comprising Northern Ireland and the Republic of Ireland, has an extensive network of tens of thousands of kilometres of public roads, usually surfaced. These roads have been developed and modernised over centuries, from trackways suitable only for walkers and horses, to...

in the Republic of Ireland
Republic of Ireland
Ireland , described as the Republic of Ireland , is a sovereign state in Europe occupying approximately five-sixths of the island of the same name. Its capital is Dublin. Ireland, which had a population of 4.58 million in 2011, is a constitutional republic governed as a parliamentary democracy,...

, especially on wide two-lane
Super two
A super two, super two-lane highway or wide two lane is a two-lane surface road built to high standards, typically including partial control of access, occasional passing lanes and hard shoulders...

 and dual-carriageway roads (the shoulders on most 2+1 road
2+1 road
2+1 road is 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. Traditional roads of at least width can be converted to 2+1 roads and reach near-motorway...

s are narrow however). They are defined within the official document the Rules of the Road as a part of the road that should normally only be used by cyclists and pedestrians. Their provision of on interurban routes in the 1970s reportedly resulted in a 50% decrease in accidents involving pedal cyclists.

The hard shoulder is usually demarcated by road markings in the form of a single dashed yellow line with the addition of yellow cat's eye
Cat's eye (road)
The cat's eye is a retroreflective safety device used in road marking and was the first of a range of raised pavement markers. It originated in the UK in 1933 and is today used all over the world....

s. On motorways, and at critical points on other routes (e.g. between junctions or sliproads, or beneath overpasses) a solid yellow line is used, denoting additional restrictions on usage of the hard shoulder. At junctions and sliproads, the yellow line peels away into the turn, with a dashed white line (with green cats' eyes) denoting a lane division following the main route (i.e. in most cases the road remains the same width, and a turn lane takes the place of the hard shoulder).

In the 2000s, Bus √Čireann coaches were allowed to use the hard shoulders on national roads into Dublin. However, dedicated bus lanes are now present on sections of some routes, such as the N7 Naas Road, and such use of actual hard shoulder is not universal.

United States

The right-hand shoulder is separated by a solid white line, and the left-hand shoulder (if the road is one-way, such as part of a divided highway
Divided Highway
Divided Highway is a compilation album by American rock band The Doobie Brothers, released in 2003. . All tracks are taken from the albums Cycles and Brotherhood .-Track listing:...

) is separated from the leftmost through lane by a solid yellow line. In many western states, the yellow line on the left-hand shoulder is supplemented by yellow reflective raised pavement marker
Raised pavement marker
A raised pavement marker is a safety device used on roads. These devices are usually made with plastic, ceramic, or occasionally metal, and come in a variety of shapes and colors. Many varieties include a lens or sheeting that enhance their visibility by reflecting automotive headlights...

s placed every few feet in order to provide additional visual and tactile feedback to drivers crossing the line. The white line on the right-hand shoulder is usually not supplemented with markers.
  • California*

On freeways in fog
Fog
Fog is a collection of water droplets or ice crystals suspended in the air at or near the Earth's surface. While fog is a type of stratus cloud, the term "fog" is typically distinguished from the more generic term "cloud" in that fog is low-lying, and the moisture in the fog is often generated...

gy areas, there is an obvious break in the line of the shoulder before every exit; this is to help drivers find their exits in heavy fog (especially dangerous tule fog
Tule fog
Tule fog is a thick ground fog that settles in the San Joaquin Valley and Sacramento Valley areas of California's Great Central Valley. Tule fog forms during the late fall and winter after the first significant rainfall. The official time frame for tule fog to form is from November 1 to March 31...

).

United Kingdom

Full width hard shoulders are usually provided only on motorways and are usually 3.3 metres wide, but there are exceptions. Some motorways do not have hard shoulders at all (for example the A57(M)
A57(M) motorway
The Mancunian Way, officially the A57, is a two mile long motorway in Manchester, England. It is part of the A57, which runs east-west through Greater Manchester and links the M602 and M67 motorways.-Route:...

) and there are a small number of dual carriageway
Dual carriageway
A dual carriageway is a class of highway with two carriageways for traffic travelling in opposite directions separated by a central reservation...

 A-roads which do possess hard shoulders (for example, parts of the A1, A2
A2 road (Great Britain)
The A2 is a major road in southern England, connecting London with the English Channel port of Dover in Kent. This route has always been of importance as a connection between the British capital of London and sea trade routes to Continental Europe...

 and A27
A27 road
The A27 is a major road in England. It runs from its junction with the A36 at Whiteparish in the county of Wiltshire. It closely parallels the south coast, where it passes through West Sussex and terminates at Pevensey in East Sussex.Between Portsmouth and Lewes, it is one of the busiest trunk...

). Hard shoulders are always marked with a reflectorised solid white line which is 20 cm wide and is provided with a rumble strip
Rumble strip
Rumble strips, also known as sleeper lines, are a road safety feature that alert inattentive drivers to potential danger by causing a tactile vibration and audible rumbling, transmitted through the wheels into the car body...

. A line of red cats' eyes
Cat's eye (road)
The cat's eye is a retroreflective safety device used in road marking and was the first of a range of raised pavement markers. It originated in the UK in 1933 and is today used all over the world....

 is also used, and is placed to the side of the line. Sometimes, a hard shoulder will be coloured differently (usually red) to that of the main carriageway lanes.

On many modern non-motorway roads, a hard strip is provided. These are usually 1 metre wide, and are bounded by thinner solid white lines, and often without a rumble strip.

Italy

The shoulder located on the side of Italy
Italy
Italy , officially the Italian Republic languages]] under the European Charter for Regional or Minority Languages. In each of these, Italy's official name is as follows:;;;;;;;;), is a unitary parliamentary republic in South-Central Europe. To the north it borders France, Switzerland, Austria and...

's highway is normally used as emergency lane in case of breakdown or is used by emergency vehicles in case of queues. According to the regulation in force it is mandatory wear a high visibility jacket when dismounting from the vehicle stopped on emergency lane.

Normally one is not allowed to drive on the shoulder but in case of traffic block, use of the shoulder is allowed to reach an exit if the exit is within 500 metres.

Australia

In a similar manner to Italy, as described above, the shoulders located on the side of Australia's highways are normally used as an emergency lane in the case of a breakdown or by emergency vehicles in the case of road congestion. However, no mandatory regulations exist to wear a high visibility jacket when dismounting from the vehicle stopped in an emergency lane.

Deaths that have occurred in emergency lanes in Australia when a vehicle has stopped

A recent study conducted by the National Coroners Information System (NCIS) in Australia has revealed twenty-nine (29) closed case fatalities (and at least a dozen case fatalities still under coronial investigation) that had been reported to Australian coroners where a person was "struck in an emergency lane after their vehicle had stopped" between July 2000 and November 2010.

External links

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