Motorway

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Image:UK motorway symbol.svg
Motorway symbol in UK, France and Ireland. Similar symbols are used in some other countries.

A motorway (in the United Kingdom, New Zealand, Pakistan, some other Commonwealth nations and Ireland) is both a type of road and a classification or designation. Motorways are highways designed to carry a large volume of traffic where a normal road would not suffice or would be unsafe, usually between cities. In the UK they are predominantly dual-carriageway roads, usually with three lanes in each direction, although four-lane and two-lane carriageways are also common, and all have grade-separated access.

Equivalent terms in other countries include autoroute, autobahn, freeway, autostrada, autopista, motorvej, autópálya, motorväg, autoput and diaľnica. In North America, the English terms freeway and expressway (including autoroutes) are used as a type of road, not necessarily as a classification type. Many highways are maintained throughout the United States as part of the Interstate Highway System. These highways are generally similar to motorways in purpose and quality.

Contents

[edit] Regulations and features

Image:Motorway.m25.arp.750pix.jpg
A Sunday in April 2004 at 5 p.m. on Britain's busy M25

In Ireland and the UK, motorways are denoted by blue signage and an M-prefixed or suffixed road number. In New Zealand motorways were historically distinguished from other roads with green signage. This changed with the establishment of Transit New Zealand, which extended the use of green signs to the entire state highway network.

The construction and surfacing of motorways is generally of a higher standard than conventional roads, and maintenance is carried out more frequently; in particular, motorways drain water very quickly to reduce hydroplaning. The road surface is generally tarmac ('black top') or concrete ('white top'). Other features are crash barriers, cat's eyes and, increasingly, textured road markings (a similar concept to rumble-strips).

[edit] Common criteria

For a road to be classified as motorway a number of conditions must be fulfilled. The following conditions generally apply:

  • Accessed at junctions by slip roads off the sides of the main carriageway;
  • Joined by link-roads at an interchange, the object of which is to allow traffic to change route without stopping or slowing significantly;
  • Traffic lights are not permitted (except at toll booths and certain interchanges) - see Ramp meter;
  • Have signposted entry and exit points at the start and end;
  • Certain types of transport are banned, typically pedestrians, bicycles, learner drivers, horses, agricultural vehicles, underpowered vehicles (e.g. small scooters, invalid carriages). In the Republic of Ireland, the "Motorway Ahead" sign at every motorway junction lists the excluded classes of vehicles. The same is true for the "Motorway Entrance" sign on motorways in most Australian states.

In the UK and the Republic of Ireland there are further restrictions:

Note that these only apply to roads directly designated as motorways. Roads may also be indirectly designated as such, see Inheritance below.

A motorway in the UK, whether by design or inheritance, must have a Statutory Instrument (SI) defining a stretch of road and sliproads as a special road under the Highways Act 1980.

[edit] Speed limits

Speed limits are generally higher than on ordinary roads. Some types of vehicle may be subject to a lower limit, while often sections of motorway are subject to lower speed limits due to local driving conditions.

Image:Motorway.m4.arp.750pix.jpg
Queues after an accident on Britain's M4

In the UK the majority of motorways and dual carriageways have a maximum speed limit of 70 mph (113 km/h) for cars. In 2004 the Conservative Party proposed increasing the motorway speed limit to 80 mph (129 km/h) on some stretches<ref>"Tories blitz 'cash-maker' cameras", BBC, August 32004.</ref>, although this did not appear in their 2005 election manifesto<ref>Template:Cite web</ref>. Some[citation needed] road safety groups feel this would be a good idea, as it more closely represents the normal (and, they claim, safe) driving practice of the majority of motorway users.

The Republic of Ireland converted to metric speed limits for roads on 20 January 2005 for consistency as most of their national roads already had distances displayed in kilometres<ref>Template:Cite web</ref>. The speed limit for motorways is 120 km/h (75 mph) - previously a 70 mph limit applied, as in the UK.

In New Zealand the speed limit on motorways is normally the top limit for state highways, 100 km/h (62 mph).

Many other roads are of near-motorway quality, but are not classified as such (generally for breaking one or more of the above rules). These are referred to as dual carriageways, which in Britain usually have the same 70 mph (113 km/h) limit. The default limit for dual carriageways in New Zealand is 100 km/h (62 mph), in Australia 110 km/h, and in Ireland 100 km/h on national roads and 80 km/h on other classes of road. Dual carriageways may be subject to a lower speed limit (e.g. in urban areas, or low-specification). In Ireland, high-quality dual carriageways may also have a special limit of 120 km/h.

[edit] Lane usage

Image:Ireland road lanes.png
Diagram showing lanes and road layout, with Irish road markings.

White dashed lines denote the lane separation, while an unbroken white line is painted alongside the median (usually known as the 'central reservation'). A white line (or in Ireland, a yellow line) on the edge of the slow lane marks the edge of the hard shoulder. The hard shoulder is not used for traffic and is reserved for breakdowns or emergency manoeuvres. Pedestrians should only use the hard shoulder to walk to emergency telephones and not for any other reason. Vehicles on the hard shoulder should activate their hazard warning lights.

Lanes closest to the edge of the road are intended for general driving – these are hence the "inside" lanes, while the lanes closest to the median are intended for overtaking (passing) slower-moving vehicles – hence they are termed "outside" lanes. Generally lanes closer to the centre of the road (outer lanes) are used for overtaking, while lanes near the edge of the road (inner lanes) are used for slower traffic (see diagram on right). Under the Highway Code in the UK, it is not permitted to overtake on the left, except in emergencies, when signs indicate drivers may do so, or when traffic is moving slowly. Similar rules apply in Germany and some other countries. With a touch of black humour, the practice is popularly known as undertaking.

Traffic should always use the lefthandmost lane as much as possible. Generally this means a vehicle should use the lefthand lane next to the hard shoulder, and use the other two lanes only for overtaking manoeuvres, moving back into the left lane once they have passed the slower vehicle(s). In heavy traffic, it is acceptable to cruise in the middle lane to pass slower vehicles to avoid constant lane changes.

A significant problem on motorways is the 'middle lane hog', a driver who drives in the middle lane when there is no reason to do so. This can be very frustrating for other drivers. Faster vehicles approaching in the left hand lane have to manoeuvre across four lanes of the motorway rather than two to overtake such a vehicle, since undertaking is deemed dangerous. Drivers of heavy goods vehicles can be especially frustrated by a middle lane hog, as their vehicles are not permitted to use the righthandmost lane on a three (or more) lane motorway under normal circumstances. Some vehicles try to induce a 'right lane hog' to move to the slower lane by keeping a very close distance, which is also considered dangerous.

In the UK lanes in a given direction are numbered from left to right as lane 1, lane 2, lane 3, etc. Lane 1 is the lane next to the hard shoulder.

[edit] Junctions

The most basic motorway junction is a two-lane flyover with four slip-roads, two on each side of the motorway, to exit or enter. A simple crossroads or roundabout is present on either end of the flyover. A rather large version of a roundabout, using two curved flyovers is sometimes used to present a single large junction for users of the slip-roads or crossing road. The slip roads leading off the motorway are known as 'exit sliproads', those leading onto the motorway as 'entry sliproads'. The precise sliproad at any junction may be identified by reference to the direction of the carriageway, for example 'northbound entry slip'.

The signal-controlled roundabout is often used in these situations and has become very common in Ireland. A far greater degree of complexity is present in Britain with varying types of Spaghetti Junction-style interchanges.

Motorway junctions are usually given a number, indicated in the UK and Ireland with a white number of a black background in the corner of signs approaching that junction. The same junction number is used in both directions on the motorway. Sometimes, where a junction is newly inserted between two existent junctions, it will be given a letter also (eg 2a ). In Ireland, only the M50 and M4 use junction numbers consistently, with some junctions of other motorways being numbered, and some not.

[edit] Location and construction

Major intercity or national routes are often built or upgraded to motorway standard. Motorways are also commonly used for ring roads around cities or bypasses of built-up areas.

In Britain there are plans to improve many motorways as well as to upgrade some roads to motorway status. In Ireland, the National Roads Authority has been connecting main cities with motorways as part of a six-year National Development Plan. The European Union has part-funded many motorway projects in the past, as part of a Trans-European Transport Networks, and there are plans to invest billions of euro in such projects in the next ten years.

Image:M6Toll.jpg
Toll charges for Britain's M6 Toll

One of the most recently constructed motorways in the UK is the M6 Toll, bypassing Birmingham and Wolverhampton, which opened in 2004 and is the only completely toll motorway in England. There are tolled sections of motorway on the M4 and M48, where they cross the River Severn at the Severn crossings. Although the crossing of the River Thames east of London on the M25 is tolled, the bridge and tunnels themselves are officially designated the A282 to permit usage by non-motorway traffic. In Ireland, the M1, M4, and M50 are all tolled, with sections of the M6, M7 and M8 likely to face tolls also in the future.

[edit] Inheritance

In the UK and Ireland certain types of traffic are not permitted on motorways. Thus, to avoid people being forced to travel illegally, there are a number of rules about stretches of road which must be designated as motorways.

In all cases, there must be an escape route for traffic not wishing or not permitted to enter the motorway. As a result, the motorway technically begins as soon as the escape route has diverged from it; for example at a grade-separated junction, the motorway starts at the junction with the exiting slip road, and the opposite slip road is also part of the motorway for this and the following reason. An exception was the A1(M) near Leeds, which was "illegal", as pedestrians could legally cross 300 yards from the start, but cyclists and other types of traffic not permitted on motorways had no way of turning back - the escape route was the Boot & Shoe a mile before. This is remedied by the A1(M) extension. On some maps the start was disguised or covered so people could not see the blunder.

As a result, this creates a less-restrictive set of rules for the standard of the road. Roads whose only destination is a motorway must be assigned motorway status, notwithstanding the possibility of their not being built to normal motorway standards. For example, the A48(M) motorway outside Cardiff begins after the last exit to St Mellons, since by staying on the dual carriageway you cannot get anywhere other than the M4 eastbound; however, it is a motorway-grade highway. A similar example in Ireland is the M6, currently a short 2 km section of the N6 eastbound that leads exclusively to the M4 motorway. The equivalent westbound section of the N6 is not signed as a motorway however.

[edit] Route numbering

In England and Wales, the numbers of major motorways were allocated to broadly follow the A-roads heading in the same direction, with a zonal pattern formed by the single-digit motorways, in much the same way as the single-digit A-roads mark out the zone boundaries for all-purpose routes. The numbering is entirely separate - the M1 and the A1 can co-exist.

In Scotland, where the Scottish Office rather than the Ministry of Transport and Civil Aviation had the decision, there is no zonal pattern, but rather the A-road rule is strictly enforced. The M8 follows the route of the A8, and the M85 became part of the M90 when the A90 was re-routed along the path of the A85.

Image:IMG 3245w.jpg
Signage on the N6 near Kinnegad in Ireland, where the designation M6 is used for a short section of motorway.

In Ireland, motorway and national road numbering does not follow the same convention. As of 2006, all motorways are part of, or form, national primary roads. These routes are numbered in series, using numbers from 1 to 33 (and, separately from the series, 50). Motorways use the number of the route of which they form part, with an M prefix rather than N for national road (or in theory, rather than R for regional road) <ref>Roads Act 1993 (Classification of National Roads) Order 2006 (PDF) - Department of Transport</ref>. In most cases, the motorway has been built as a bypass of a road previously forming the national road (e.g. M7 bypassing roads previously forming the N7) - the bypassed roads are reclassified as regional roads, although updated signposting may not be provided for some time, and adherence to signage colour conventions is lax (regional roads have black-on-white directional signage, national routes use white-on-green).

The M50, an entirely new national road, is an exception to the normal inheritance process, as it does not replace a road previously carrying an "N" number. The M50 was nevertheless legislated as the "N50" route (despite having no non-motorway sections). The M50's designation was chosen as a recognisable unique number (as of 2005 N34 is the next unused national primary road designation). In theory, a motorway in Ireland could form part of a regional road <ref>Roads Act 1993 (Classification of Regional Roads) Order 2006 (PDF) - Department of Transport</ref>.

In Hungary, similarly to Ireland, motorway numbers can be derived from the original national highway numbers (1-7), with an "M" prefix attached, eg. M7 is on the route of the old Highway No. 7 from Budapest towards Lake Balaton and Croatia. New motorways not following the original Budapest-centered radial highway system get numbers M8, M9, etc., or M0 in the case of the ringroad around Budapest.

In New Zealand, motorway numbers are also derived from the state highway route which they form a part of, but unlike Hungary and Ireland they are not distinguished from non motorway sections of the same state highway route. In the cases where a motorway acts as a bypass of a state highway route, the original state highway is either stripped of that status or renumbered (as in the case of the Northern motorway extension from Albany to Silverdale, north of Auckland, where the new motorway was designated as part of State Highway One, while the old state highway one route linking Albany to Silverdale was designated State Highway 17).

[edit] History

The first motorway built was the Autostrada dei laghi, inaugurated on September 21 1921 in Milan. It linked Milan to Varese. Piero Puricelli, the engineer who designed this new type of road, decided to cover the expenses by introducing a toll to be paid by whoever used the motorway. <ref>Template:Cite web</ref> <ref>Template:Cite web</ref>

[edit] References

<references/>

[edit] See also

[edit] External links

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bs:Autoput da:Motorvej cs:Dálnice de:Autobahn es:Autopista fr:Autoroute hr:Autocesta it:Autostrada hu:Autópálya ja:高速道路 nl:Autosnelweg no:Motorvei nrm:Motoroute pl:Autostrada ru:Автомагистраль sco:Motorwey sk:Diaľnica sv:Motorväg zh:高速公路

Motorway

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