Motorway
A motorway (UK, Ireland) is both a type of road and a classification. Used to carry large volumes of traffic where a normal road would not suffice or would be unsafe. They are always dual-carriageway, with at least four lanes (two each direction) and grade-separated interchanges.
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2 Features 3 Location and Construction 4 See Also 5 Similar concepts to Motorway 6 External Links |
For a road to be classified as motorway a number of conditions must be fulfilled. Interchanges must be accessed by slip-roads off the sides of the main thorough-fare. Traffic lights are not permitted and the median must remain unbroken. Emergency phones must be provided at a certain frequency. The start and end of a motorway must have signposted entry and exit points. Many roads in Britain and Ireland are of near-Motorway quality, but are not classified as such (generally for breaking the above rules). These are referred to as dual-carriageways, which in Ireland have a lower speed limit.
In both countries, motorways are denoted by blue signage (and an M-prefixed road number). Speed limits are generally higher than on ordinary roads, with an absolute limit of 70mph in both the UK and Ireland. Lanes closest to the edge of the road (inside lanes) are intended for general driving, while the outer lanes are intended for overtaking (passing) slower moving vehicles. Except in certain circumstances, and unlike on North American freeways, drivers are not permitted to pass on the inside. (With a touch of black humour, the latter practice is popularly known as undertaking.) Learner driverss, pedestrians, cyclists and underpowered vehicles (e.g. small scooters) are generally banned from motorways.
The road surface is generally dark-coloured asphalt. White dashed lines denote the lane separation, while an unbroken white line is painted alongside the median. A yellow dashed 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. Other features are crash-barriers, cat's eyess and increasingly, textured road markings (similar concept to rumble-strips).
Junctions or interchanges can vary in degrees of intricacy. 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. An Irish invention is the signal-controlled roundabout which is often used in these situations. A further degree of complexity is present in Britain with varying types of Spaghetti Junction style interchanges.
Motorways are commonly used for ring roads around cities or bypasses of built-up areas. Examples of ring-road motorways are the M25 around London and M50 around Dublin. Major intercity or national routes are often built or upgraded to motorway standard.
In Britain there are plans to upgrade many motorways as well as upgrade some roads to motorway status. In Ireland, the main cities are being connected by motorways as part of a six-year National Development Plan. The EU has part-funded many motorway projects in the past, as part of a Trans-European Transport Network, and there are plans to invest billions of Euro in such projects in the next 10 years.
Regulations
Features
Location and Construction
See Also
Similar concepts to Motorway
External Links