Misplaced Pages

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88-498: The Hindhead Tunnel , opened in 2011, is part of the 4-mile (6.4 km) dual-carriageway that replaced one of the last remaining stretches of single-carriageway on the A3 road which connects the cities of London and Portsmouth . It was built to bypass the village of Hindhead in Surrey . At 1.14 miles (1.83 km) in length, the tunnel is the longest non- estuarial road tunnel in

176-407: A divided highway ( AmE ) is a class of highway with carriageways for traffic travelling in opposite directions separated by a central reservation (BrE) or median (AmE). Roads with two or more carriageways which are designed to higher standards with controlled access are generally classed as motorways , freeways, etc., rather than dual carriageways. A road without a central reservation is known as

264-428: A single carriageway regardless of how many lanes there are. Dual carriageways have improved road traffic safety over the years and over single carriageways and typically have higher speed limits as a result. In some places, express lanes and local or collector lanes are used within a local-express-lane system to provide more capacity and to smooth out traffic flows for longer-distance travel. A very early (perhaps

352-530: A 'motorway/freeway' standard divided road. Most states only declare a divided road as a 'motorway' or 'freeway' if access is completely controlled . Speed limits are usually 100 km/h or 110 km/h. Weald Basin The Weald Basin's formation commenced during the Carboniferous , with the rocks which are today basement deposited within a low swamp providing coals which were exploited to

440-414: A broken line indicating passing zones and a solid line indicating no passing zones and solid white baseline shoulder stripes. On undivided roads with more than one lane in each direction, the center is normally marked with a double solid line. The double solid stripe denotes that it is illegal to pass on the other side of the center line. Multilane one-way carriageways use broken white lines between lanes;

528-478: A built up area is indicated by the presence of street lights; on lit dual carriageways that are not considered to be in a built-up area, the speed limit will be clarified with intermittent signs. Although in Ireland the term dual carriageway technically applies to any road with physically separated lanes, it is usually used only to refer to those route sections that do not have a motorway designation. Most often it

616-582: A central median, usually fitted with guardrails. The most heavily used expressways in Croatia is the D10 road , connecting capital Zagreb to Vrbovec and Križevci . In the United States, this type of road may be called a divided highway, boulevard, parkway, expressway, freeway, or interstate, and has a grassy median or Jersey barrier separating the traffic directions. With few exceptions, all roads in

704-559: A deep cutting to the south of the tunnel with a new junction for Hindhead and Hammer at its southern end. An equestrian and pedestrian bridge, the Miss James Bridge, crosses the cutting between tunnel and junction, and includes heathland planting to link the habitats on either side of the cutting. Advance works started in January 2007, and main construction works, including the tunnelling, started in 2008. Excavation work from

792-484: A freeway from the 1950s to 1970s. Opened to traffic in 1940, the 160-mile-long (260 km) Pennsylvania Turnpike was the first rural dual carriageway built in the United States. By 1955 several states had built dual carriageway freeways and turnpikes and in 1957 the Interstate Highway System began. Completed in 1994, the major highway system links all the major cities of the United States. In

880-467: A lack of funding elsewhere, partial controlled-access "expressways" and limited-mobility divided arterial roads are more common in the western provinces where there are no specially numbered systems of freeways. On some portions of Ontario 's 400-series highway network, the median may be either steel guardrail or an Ontario tall-wall barrier rather than an unpaved strip, particularly in urban areas. Some partial limited-access divided highways such as

968-502: A median barrier preventing left turns (motorists have to use a "turnabout" overpass to access exits on the opposing direction). Speed limits in Canada are usually 80 to 90 km/h on signalized divided highways and 100 to 120 km/h on freeways. In Australia, dual carriageways are referred to in some regions as divided roads, though there is no official terminology. Each state's road agency has its own definition of what constitutes

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1056-501: A narrow strip of trees down the middle. In 1907 the Long Island Motor Parkway opened, and roughly 20% of it featured a semi-dual-carriageway design. The New York City Belt Parkway system, which was built between 1907 and 1934, also pioneered the same design. However the majority of it featured concrete or brick railings as lane dividers instead of grass medians. In the year of 1924 the first Italian autostrada

1144-605: A new standard was set to designate certain high-quality routes formally as "Expressways". Many roads such as the A1 , the A14 , the A19 and the A42 are built to a high quality, with grade-separated junctions, full barriers at roadside and central reservations and, in some cases, three lanes of traffic. They may still fall short of motorway standard in terms of hard shoulders, the height of overpasses or

1232-534: A number of brickworks exploit the lower Cretaceous clays. The inversion of the Weald Basin throughout the late Cretaceous and early Tertiary resulted in the formation of the Wealden Anticline and a number of smaller anticlines within the larger structure. The discovery in 1897 of natural gas while drilling for water at Heathfield railway station provided fuel for the first natural gas lighting in

1320-500: A precedent for future highways. Although it, like the first autostrada , did not feature a dual-carriageway design, it inspired the mass construction of future high-speed roadways. During the 1930s, Germany, Italy, and the Soviet Union began construction of a network of dual carriageway expressways. By 1942, Germany had over 3,200 km (2,000 mi) of dual carriageway roads, Italy had nearly 1,300 km (810 mi), and

1408-652: A re-evaluation of road tunnel safety throughout Europe. An EU directive passed in 2004 laid down the minimum safety requirements for road tunnels within the EU and EFTA that exceed 500 m in length and that are part of the Trans-European Road Network (TEN). Although the Hindhead tunnel is more than 500 m in length, it does not carry part of the TEN road network so legally does not need to comply with

1496-416: A result of their misjudging the speed of approaching traffic on the other carriageway when doing so. The majority of dual carriageway roads now have barriers. Some are heavy concrete obstructions which can bounce a vehicle back into the path of other traffic; others are made from steel ropes mounted on moderately weak posts, where the rope cuts into the vehicle body to slow the vehicle while keeping it against

1584-423: A total of 737,000 cubic metres of spoil having been excavated. The application of the waterproof membrane and the installation of the secondary lining only started once all the excavation and primary lining were complete. The waterproof membrane was sprayed onto the primary lining and the pre-cast invert and side section installed. Spraying of the secondary lining onto the crown of the tunnel was scheduled as part of

1672-510: Is autovía (literally autoway ). All of them are government-owned and not tolled. First-generation autovías, built in the 1980s and early 1990s, were just duplications in parallel of existing roads, as shown in the photograph. Modern autovías are two carriageways built from scratch, leaving the old road they replace as an alternative route for pedestrians, bicycles and other non-motorized vehicles. Private properties may have direct access to an autovía, as well as bus stops and gas stations in

1760-399: Is national roads (roads with a route number prefix of N ; e.g. N8 ) that are built as or upgraded to dual carriageway. A number of non-national roads (for example, regional roads ) are dual carriageway, for example in urban areas near or in cities, or where the road was part of a national route. Dual carriageways of this class differ from motorways in a number of ways. The hard shoulder

1848-450: Is demarcated with a dashed yellow line (as opposed to an unbroken yellow line on motorways). The standard speed limit of 100 km/h (62 mph) for national routes usually applies (by default the limit is 80 km/h (50 mph) for non-national roads, even if dual carriageway). Local authorities have the power to apply a limit of up to 120 km/h (75 mph) as used on most motorways (The High Quality Dual Carriageway section of

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1936-408: Is heavily fractured and has mean fracture centres varying from 190 to 815 mm (7.5 to 32.1 inches). The southern end of the tunnel however passes through the "less competent" Upper Hythe A and B layers which are described as "medium-dense thinly bedded and thinly laminated, clean-to-silty and clayey fine and medium sand with subordinate weak-to-strong sandstone, cherty sandstone and chert ". Most of

2024-674: Is today Ashdown Forest . However it is likely that erosion kept pace with uplift, resulting in large quantities of sediment supply to the North Sea and the English Channel Coal seams were discovered when test boring for an early proposal for a Channel Tunnel at Dover in 1890. This led to the development of four deep mines in the Kent Coalfield in the early 20th century. The Weald Basin has yielded significant quantities of gypsum from Jurassic Purbeck beds and

2112-577: The Autobahn network programme but still have the blue signs (e. g. the B 59 , formerly A 540 near Grevenbroich ); and on the other hand some former non- Autobahn (yellow) motorways have been added to Autobahn budgeting but the signs have not been changed either (e. g. parts of the B 6 , now A 36 in the north of the Harz highland area in Saxony-Anhalt). Motorways that are neither in

2200-709: The Early Jurassic a north and east shallowing mud-dominated shelf developed. As a result of the Alpine orogeny the basin was squeezed between the basement to the north and the south, this resulted in the reactivation of the formerly normal faults into minor thrusts (as they had been during the Variscan Orogeny ) and the formation of the Wealden Anticline . The region's two surface structural highs (areas of crust and rocks which are uplifted),

2288-500: The Hanlon Parkway and Black Creek Drive have stop-controlled at-grade intersections and private entrances, but have sufficient right-of-way to convert them to full freeways with interchanges if traffic warrants. There are also RIRO expressways , such as Highway 11 and a portion of Highway 35 , which are not full freeways since they allow access to existing properties, but traffic speeds are faster than regular roads due to

2376-708: The Mediterranean world . This influx of road activity necessitated the construction of a dual thoroughfare as the road approached the Porta Portese , the corresponding gate in the Aurelian Walls of Rome for the Via Portuensis . One claim for the first divided highway in the United States was Savery Avenue in Carver, Massachusetts , first built in 1860, where the two roadways were separated by

2464-707: The N1 between the end of the M1 and the border with Northern Ireland and the N25/N22 Ballincollig Bypass in Cork are the only route sections with such special limits). Traffic lights and junctions are permitted at grade on dual carriageways. For older sections of dual carriageway, this has resulted in fewer flyover junctions. Newer dual carriageway sections are usually near motorway standard, with grade-separated junctions, but may not be designated as motorways due to

2552-737: The Thursley side of the works dating from the 18th or 19th century. It is probable that lime produced by the kilns used limestone or chalk from Petersfield 25 kilometres (16 mi) away and would have been used to counteract the acid nature of the soil. The main contractors received the Preservation Award at the 2011 Tunnels and Tunnelling Awards and were Overall Winners at the 2012 ICE Thames Valley Engineering Excellence Awards. 51°06′39″N 0°43′56″W  /  51.1109°N 0.7322°W  / 51.1109; -0.7322 Dual-carriageway A dual carriageway ( BrE ) or

2640-572: The Wealden Anticline and the Channel High, are superimposed upon earlier, Mesozoic basins, (the Weald and Channel basins). This nearly exact superimposition of compressional features upon underlying formerly extensional features exemplifies perfectly the principles of structural inversion across a large and well defined geologic feature. The overall uplift produced by the Tertiary inversion in

2728-680: The autobahn network nor in the Bundesstraße network are given black on white signs, following the same sign code as high-speed dual carriageways—this is mostly seen on urban trunk roads. Italian Highway Code ( Codice della strada ) divides dual carriageways into three different classifications: Italian type-B and type-C roads do not follow a specific numbering criterion. They may be numbered as Strade Statali (SS; "state roads"), Strade Regionali (SR; "regional roads"), Strade Provinciali (SP; "provincial roads") or Strade Comunali (SC; "municipal roads"). The Spanish word for dual carriageway

Hindhead Tunnel - Misplaced Pages Continue

2816-730: The A3 through Hindhead had been recognised for many years with a route study being undertaken between 1970 and 1976. In 1983 some nine alternatives for the A3 were investigated by the Department for Transport, but assessment showed that only one which went around the north and west side of the Punch Bowl (the "Red Route"), crossing the Smallbrook Valley was viable. A public consultation on the route met with opposition and two alternatives were suggested both of which drew less support than

2904-544: The Devil's Punch Bowl contour, has been returned to nature. From the end of that section, the remainder of the old A3 as far as Thursley Junction is used as a local road. The higher level pre-1826 Old Portsmouth Road route across the Devil's Punch Bowl still exists, and is used a pedestrian and cycle path, and as a bridleway . Besides providing a route across the Devil's Punch Bowl, it also provides access to Gibbet Hill , with its extensive views of Southern England. The tunnel

2992-475: The Local Government Act 2001. Accordingly, hard shoulders are included wherever feasible to provide for the resulting pedestrian and cyclist traffic, and are present on much of the national route network. These hard shoulders may also be used as running lanes by motorised traffic under certain conditions. Until 2005, many motorways and dual carriageways in Ireland did not have crash barriers in

3080-554: The Soviet Union had 400 km (250 mi). What may have been the world's first long-distance intercity dual carriageway/freeway was the Queen Elizabeth Way in Southern Ontario in Canada, initially linking the large cities of Toronto and Hamilton together by 1939, with construction on this stretch of the present-day Queen Elizabeth Way beginning in 1936 as "Middle Road". It was gradually upgraded to

3168-659: The UK, although the term "dual carriageway" applies to any road with physically separated lanes, it is frequently used as a descriptive term for major routes built in this style. Such major dual carriageways usually have two lanes of traffic in each direction, with the lane nearest the centre being reserved for overtaking. Occasionally dual carriageways have only one lane in each direction, or more than two lanes each way (sometimes to permit easier overtaking of slower uphill traffic). Different speed limits apply on dual carriageway sections from those that apply on single carriageway sections of

3256-469: The UK. As of August 2013 there was significant opposition to hydraulic fracturing developing in southeast England centred on Balcombe where an exploratory well was planned and the Balcombe drilling protest was in progress. A BGS/ Department for Energy and Climate Change (DECC) report from May 2014 suggest that there is the possibility for the extraction of light tight oil (LTO) in Weald Basin and

3344-592: The United Kingdom, and takes the road beneath the Devil's Punch Bowl , a Site of Special Scientific Interest . A naval dockyard has existed in Portsmouth since at least Tudor times, giving significant importance to the road linking that city with London. The original 73-mile (117 km) route skirted the north-western limits of The Weald climbing to the summit of Gibbet Hill close to Hindhead . In 1826

3432-705: The United Kingdom. The existence of the same strata within the Weald basin which are the source rocks for the Wytch Farm oilfield in Dorset led to an interest in the petroleum potential of the Wealden anticline, with exploration taking place on Ashdown forest examining the Ashdown Anticline, a large structure over 30 km long x 7 km wide, located in the centre of the Weald Basin in north Sussex ; significant quantities of natural gas were found but oil

3520-428: The barrier until it has stopped. Often on urban dual carriageways where the road has been converted from a four-lane single carriageway the central reservation will not be substantial: often just a small steel divider to save space. Turning right (that is, across the line of traffic heading in the opposite direction) is usually permitted only at specific locations. Often the driver will be required to turn left (away from

3608-459: The basis of their structure these roads have, comparable to the German autobahn , the legal foundation that no default speed limit exists (design speed 130 km/h), although the standard advisory speed limit ( German : Richtgeschwindigkeit ) still exists. Nevertheless, expressways are often given speed limit signs. Exit signs. At the moment some (blue) motorways have been taken out of

Hindhead Tunnel - Misplaced Pages Continue

3696-556: The carriageway. The tunnel has two power supplies, one via the north portal and the other via the south portal, each backing the other up in the event of failure. Ventilation is provided by fans mounted above the traffic, though in normal circumstances they will not be operational. Electronic equipment includes linear heat detectors , radar coverage and 104 CCTV cameras that can pinpoint incidents, intelligent lighting and LED cat's eyes and comprehensive fire-fighting systems. The tunnel approaches have cross-over systems that enable

3784-691: The central reservation, the policy being to use a wider median instead. Crash barriers are now mandatory for such routes, and wire cabling or full crash barriers (depending on whether or not the route is a motorway, and median width) have been fitted to existing routes. Between 2000 and 2010, three major types of dual carriageway were built on national road schemes in Ireland: In Germany the term Autobahnähnliche Straße (motorway-like road) refers to roads that are similar to German autobahn in grade-separation and signage. Most of them are designated as Kraftfahrstraßen (expressways), which means that

3872-628: The construction was completed, the section of the previous route of A3 from the A287 intersection in Hindhead southwards was renamed the A333 and the 250 m (820 ft) section from the intersection northwards up to the National Trust car park has been retained for access to the car park and other properties. The section from the car park in the London direction, which was created in 1826 to follow

3960-642: The cost of the project to £371 million, with the underground section costing £155,000 per metre (£142,000 per yard) making that section of road the second most expensive road in the UK per unit distance, after the Limehouse Link tunnel . The Hindhead tunnel runs through a sequence of fine grained strata of the Lower Greensand Group , which were laid over Weald Clay during the Lower Cretaceous period (70–140 million years ago) on

4048-524: The day and had an accident rate 40% higher than the national average for that class of road. By 2000 the A3 between Southfields and Havant had been built to dual carriageway standards for its entire length apart from the 3.4-mile (5.5 km) Hindhead section (there are still sections of single carriageway within London and Portsmouth). The termini of the northern and southern sections of dual carriageway were at altitudes of 180 m (590 ft) and 190 m (620 ft) above sea level respectively and

4136-413: The directive. Cross-connection tunnels have been constructed at 100 metre intervals to allow for emergency evacuation to the other tunnel should there be an incident. Although the EU directive requires laybys at intervals not exceeding 1000 metres for TEN-T tunnels that do not have emergency lanes, the Hindhead tunnel does not have any laybys, but it does have 1.2 m verges on either side of

4224-435: The dual carriageway) in order to loop around to an access road that permits crossing the major road. Roundabouts on dual carriageways are relatively common, especially in cities or where the cost of a grade-separated junction would be prohibitive. Where space is even more limited, intersections may be controlled by traffic lights. Smaller residential roads adjoining urban dual carriageways may be blocked off at one end to limit

4312-423: The eastern Wealden basin has been estimated to be as much as 1525 m; which as a result of the large amount of Mesozoic sediments does not reveal the underlying Paleozoic basement. Utilising estimations of the original thickness of Chalk (400–460 m) and other Mesozoic strata indicate a complex fold structure which, in the event it was not eroded during uplift, attained a crestal elevation of 1400 m over what

4400-607: The entire length featured a dual-carriageway design. In the early 1930s, it was extended southward all the way to Naples and northward to Florence. Most of the original routing was destroyed by the Allies in World War II. By 1930 several US and European cities had built dual-carriageway highways, mostly to control traffic jams and/or to provide bypass routes for traffic. In 1932 the first German autobahn opened between Cologne and Bonn. It ran 21 km (13 mi) and became

4488-667: The federally funded Interstate Highway System are fully controlled access divided highways known as freeways . A broader definition, expressways , includes both freeways and partial limited-access divided highways, and "expressway" is often used specifically to refer to the latter. United States Numbered Highways , state highways and other locally maintained highways may also be divided. Speed limits on rural divided highways range from 65 to 75 miles per hour (105 to 121 km/h), with some portions as high as 80 miles per hour (130 km/h). One privately run toll road in Texas, SH 130, has

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4576-484: The finalisation of the excavation works. On Sunday, 14 May 2011, one and a half months before the tunnel was due to open, the contractors staged an open day when 7,000 pedestrians were able to walk the full length of the tunnel while local music groups performed at the north end of the tunnel. These included the Haslemere Town Band, who performed the "Devil's Punch Bowl March" as the first VIPs emerged from

4664-611: The first) example of a dual carriageway was the Via Portuensis , built in the first century by the Roman emperor Claudius between Rome and its harbor of Portus . The route between the city and the port experienced a great deal of commercial and pedestrian traffic, as Portus served as the primary avenue for the grain shipments of the Cura Annonae into Rome, as well as transporting the majority of goods imported from across

4752-673: The generic speed limit is 120 km/h (75 mph), minimum speed is 60 km/h (37 mph), driving backwards is strictly prohibited, and they shall not have at-grade junctions. Dual carriageways or expressways in Croatia (Croatian: brza cesta ) are non- tolled roads with 2 or more lanes in each direction, but without emergency lanes . The main motorways in Croatia are also dual carriageways, but they have emergency lanes and tolls. Many bypasses and beltways of smaller cities in Croatia have been recently constructed or planned as dual carriageways. All dual carriageways in Croatia house

4840-571: The geometry of the early fault systems in the Weald Basin reveal that for the early history of the basin a series of steep normal faults to the north were active against the London-Brabant Massif , but it is not clear whether this reflects a syn-rift origin for these rocks. The Weald basin gently subsided throughout the Jurassic, Cretaceous and Early Tertiary leading to a thick succession of sedimentary rocks being deposited. During

4928-544: The hard shoulders. A controlled-access highway (motorway) in Spain is referred to as autopista (literally autotrack ). They may be operated by private companies and be tolled. The two major accesses to Spain from France, AP-7 into Catalonia and AP-8 into the Basque Country , are autopistas. In comparison, the prime road between Spain and Portugal is the photographed autovía A-5 . In both autopistas and autovías,

5016-478: The highest speed limit in the United States at 85 miles per hour (137 km/h). Urban divided highways which are at grade and typically have much lower speed limits are sometimes called boulevards . In keeping with the U.S. Department of Transportation 's Manual on Uniform Traffic Control Devices (MUTCD), since the early 1970s all divided highways are striped by color to show the direction of traffic flow. Two-way undivided roads have an amber center line, with

5104-463: The initial support for the tunnel. At the southern end, where tunneling passed through the Lower Hythe sands, the primary lining was supplemented with 4 m (13 ft) "pins" to provide more support. Emergency interconnecting cross passages are located at intervals of 100 m (330 ft) to facilitate movement of pedestrians between tunnels in case of emergency. Ancillary works include

5192-680: The introduction the Irish Planning system in 1964. Today Irish planning policy prohibits such development on National Primary or National Secondary roads where the speed limit exceeds 60 km/h (37 mph). This policy results from concerns expressed by the National Roads Authority. A local authority is not obliged to implement this policy and can disregard this policy at its own discretion. This would usually only occur in exceptional circumstances or where planners are overruled by elected councillors using section 140 of

5280-708: The lanes of an existing road (for example US Highway 33 between Elkhart and Goshen in northern Indiana). Like other countries, there are several types of divided highways; fully controlled-access divided routes with interchanges (commonly known as "freeways" in the United States, Australia, and regionally within Canada), expressways that often include a mix of interchanges and traffic signals, and divided arterial roads that are almost entirely stop-controlled. Unlike some other countries, divided dual carriageways in Canada are seldom equipped with traffic circles , roundabouts, or rotaries as alternatives to stoplights. In Canada,

5368-522: The margins of the subsiding Weald Basin . The Greensand group consists of the Hythe Beds, which overlay a 10 to 20 m (33 to 66 ft) layer of Atherfield Clay. The Hythe beds consist of the Upper Hythe bed, which has a four substrata identified by the letters "A" to "D", and the Lower Hythe bed, which has two strata which are identified by the letters "A" and "B". Originally that whole area

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5456-535: The median-side baseline is solid amber, and the right sideline is solid white. Frequently in the U.S. the two carriageways are separated by some distance (wide medians with small forests or even hills in them), but drivers can always tell whether the roadway is two-way or one-way—and, if one-way, the direction in which the traffic flows—by looking at the striping coloration. For an example, see inset showing U.S. Route 52 near Lafayette, Indiana . Some divided highways have been turned into undivided highways by widening

5544-567: The mountain belt can be seen today in Devon and Cornwall in what is known as the Cornubian Massif. Unlike in Devon and Cornwall the deformation caused little or no metamorphism. The mountain belt collapsed soon after the orogeny, leading to the former northward thrusts to be reactivated as normal faults, and led to the formation of the Weald basin, which developed as an extension of the considerably larger Wessex Basin . Reconstructions of

5632-406: The nature reserve to the other. Among the artefacts found was an old milestone that was discarded during the rebuilding of the road in 1826. The 1811 Ordnance Survey map was used to identify the original position of the stone where it has since been re-erected. The pre-1826 road is now a pedestrian way to Gibbet Hill . Other artefacts of archaeological interest included two lime kilns found near

5720-678: The need to preserve access to adjoining property or to the absence of a non-motorway alternative route. Also, dual carriageways that are not motorway classified do not need to be equipped with emergency phones. Motorway restrictions only apply to motorway sections, rather than all dual carriageway sections of national roads (these are signposted with the N prefix on the route number, rather than M ). Some national secondary roads , and regional roads in particular often have houses, schools and other developments fronting on to them. Less important national primary roads , and older sections not yet upgraded may also feature such developments built before

5808-491: The north and east in Kent , but boreholes drilled in the 19th century failed to find this deposit in the area of the Weald. The Carboniferous coals may be overlain by early Triassic sediments. The sediments were uplifted and faulted within the Variscan Orogeny , with the land now occupied by the Weald Basin being a low external fold belt to the main orogeny, which was located within the present day English Channel. The remnants of

5896-403: The north portal began on 1 February 2008. Two Liebherr diggers were employed, one on each tunnel with work being carried out around the clock, seven days a week. Work from the south portal began on 14 May using a single Liebherr digger to dig both tunnels. Since the south portal was close to housing, work was restricted to a single shift five days a week. The poorer ground at the southern end of

5984-487: The northern portion 3.9 m/day. Prior to breakthrough, only part of the tunnel – the semicircular cross-section above the bench – was excavated. Excavation of the bench in the southbound tunnel began on 9 July 2008. This work progressed much quicker than the initial excavation work as several faces could be opened up at once. Again, the primary linings were sprayed onto the workings as digging progressed. The excavation and primary linings were completed on 31 March 2009 with

6072-522: The number of junctions on the dual carriageway; often other roads will pass over or under the dual carriageway without an intersection. A dual carriageway with grade-separated junctions and which meets other requirements may be upgraded to motorway standard, denoted by an (M) added after the road number (e.g. " A1(M) " or " A38(M) "). Unlike in Ireland, there was no official terminology for 'high-quality dual carriageways' until April 2015, when in England

6160-522: The outset a tunnel was built rather than a cutting being dug to avoid spoiling an area of outstanding natural beauty and a Site of Special Scientific Interest , much of which is owned by the National Trust . Before digging started an environmental survey was carried out. Common lizards, adders and slow-worms found at Boundless Valley were relocated to National Trust land at Highcombe Edge while grass snakes were taken to Hurthill Copse. Tree felling

6248-646: The police to direct all traffic through one of the tunnels should the other be closed as a result of an incident or for maintenance. Due to part of the original A3 having been returned to nature, it is not possible to use the old road in an emergency. However the South East of England has a comprehensive road network, and redirection of traffic from the A3 to the M3 would increase the Kingston to Portsmouth journey from 65 miles (105 km) to 89 miles (143 km). From

6336-406: The proposal. Among the alternative proposals was one for a surface route following a more westerly line that would avoid building a tunnel (an adaptation of the "Red Route"). Despite being significantly more expensive than building a surface road, a tunnel was preferred after two alternative surface schemes were rejected on environmental grounds. The decision to put part of the road in a tunnel pushed

6424-512: The proposed route which in 1988 became the preferred route. Subsequent environmental surveys showed that this route would have substantial adverse impacts resulting in the proposal to adapt an earlier scheme by including a tunnel to avoid the most sensitive parts of the route. The scheme entered the government's targeted programme of improvements in 2001. A public inquiry was held in September 2004 to hear objections and to consider alternatives to

6512-453: The quality of intersecting junctions. The national speed limit applies on dual carriageways (unless it is in a ' built-up area ', or a lower limit is posted), which is as follows: A dual carriageway in a built up area will have a statutory speed limit of 30 mph (48 km/h) unless otherwise sign-posted. It is common for such urban dual carriageways to have an increased speed limit of 40 mph (64 km/h). A road deemed to be in

6600-524: The road was rebuilt around the Devil's Punch Bowl to ensure that the gradient was no more than 5%. The road became part of the A3 when road numbering was introduced in the 1920s. By the start of the new millennium most of the A3 had been dualled; of the route from Southfields to Havant , only the section that passed through Hindhead and the Devil's Punch Bowl was still single carriageway. This section, which passed through an Area of Outstanding Natural Beauty (AONB), operated at or above capacity for much of

6688-508: The roads allow higher speed traffic than is common on other roads. This in turn requires them to have dual carriageways in most cases. An exception is the 2+1 road system in some rural areas; these roads are also referred to as expressways. Autobahnähnliche Straßen mostly are colloquially referred to as gelbe Autobahn (yellow motorway) because they have the same technical standard as the Autobahn but have black on yellow signs instead of

6776-403: The same class of road, except in cities and built-up areas where the dual carriageway is more of a safety measure. When first constructed, many dual carriageways—including the first motorways—had no crash- or other barriers in the central reservation. In the event of congestion, or if a driver missed their exit, some drivers made U-turns onto the opposite carriageway; many accidents were caused as

6864-433: The single carriageway linking them followed a winding route around the Devil's Punch Bowl , reaching an altitude of 260 m (850 ft). The Hindhead Tunnel project shortened the route by about 300 m (980 ft) and routed the road through a tunnel whose northern and southern portals are at altitudes of 190 m (620 ft) and 200 m (660 ft) above sea level respectively. The need for improvements to

6952-646: The term "divided highway" is used for this type of road, and the segment between the roadways is referred to as a "median". There may be gaps in the median strip of a partially controlled-access road to allow turning and crossing. More informally, a divided highway may be referred to as "twinned". This stems from the practice of "twinning" an existing two-lane highway and converting it into a divided highway. Such highways in southern Ontario, southern Quebec, and parts of Atlantic Canada usually feature full controlled-access with interchanges where robust federal and provincial funding has made such freeways possible. However, due to

7040-411: The tunnel also slowed progress. The primary linings were sprayed onto the tunnel with the spraying operation following the excavation operation by about two metres when digging through sandstone and about one metre when digging through sand. Breakthrough was achieved on both tunnels on 26 February 2009, 250 m from the south portal. The extraction rate for the southern portion was 1.2 m/day and for

7128-562: The tunnel is above the predicted water table. Access to the new section of road from the north is via the original A3 with access to the old A3 being provided from the Thursley Junction, completed in 2005, about one kilometre beyond the northern limit of the Hindhead Tunnel works. The new road can be accessed from the south using the original A3 with new access points being provided by new junctions at Hazel Grove. After

7216-636: The tunnel. This had been composed especially for the occasion by 16-year-old Band member, Eric Foster. The opening ceremony itself, to which the public was not invited for safety reasons, was performed by the Secretary of State for Transport Philip Hammond on 29 July 2011. Fatal fires in the Mont Blanc Tunnel and the Gotthard Road Tunnel in 1999 and 2001 respectively, resulting in the temporary closures of these tunnels, led to

7304-414: The white on blue signs used on the Autobahn motorway network. These are generally high-speed arterial roads in larger cities or important roads within a federal state that do not connect to major cities, so that they do not fall under the federal budget for the Autobahn network. The federal road Bundesstraße 27 is an example where about half of its length is upgraded to a high speed motorway standard. On

7392-580: Was absent. Oil and gas have subsequently been found at a number of sites in the Weald including Singleton and Storrington in West Sussex, Godstone and Lingfied in Surrey, and Cowden in Kent. In 2009 remaining recoverable oil reserves in the Weald Basin were estimated at one and a half million tonnes. In 2010 the Weald Basin contributed 18% of onshore gas and less than 5% of onshore oil production in

7480-512: Was covered by the Bargate Beds, but when the Weald was uplifted , the Bargate Beds were eroded away. Most of the tunnel passes through the Upper Hythe C and D layers and the Lower Hythe A layer, which are described as "Weak, locally very weak to moderately strong, slightly clayey fine-to-medium sandstone with occasional thin beds of clayey/silty fine sand" and typically has Uniaxial Compressive Strength (UCS) values of 2–5 MPa. The rock

7568-548: Was excavated using mechanical diggers rather than a tunnel boring machine (TBM) as the TBM would only have been cheaper if tunnel was longer than 2.5 km (1.6 miles). As a result, the excavated part of the tunnel was horse-shoe in shape rather than circular, and the amount of spoil removed was 20% less than would have been the case had a TBM been used. Each tunnel has an approximate excavated diameter of 11.6 m (38 ft). A 200 mm (8 inches) shotcrete primary lining provided

7656-528: Was opened running 55 km (34 mi) from Milan to Varese . It featured a broad road bed and did not feature lane dividers except near cities and through the mountains. The London end of the Great West Road became Britain's first dual carriageway when it was opened in 1925 by King George V . In 1927 the Rome bypass was opened. It ran 92 km (57 mi) bypassing Rome to the east. Almost

7744-421: Was scheduled to minimise disruption to nesting birds and to other wildlife and in certain instances, animals such as dormice were removed to similar habitats elsewhere. After the works were completed, 200,000 trees were planted on the route of the old road. The restoration of the old road to nature removed a barrier that prevented the migration of ground-nesting birds, such as woodlarks and nightjars from one part of

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