The M5 is an
expressway
Expressway may refer to:
* Controlled-access highway, the highest-grade type of highway with access ramps, lane markings, etc., for high-speed traffic.
* Limited-access road, a lower grade of highway or arterial road.
*Expressway, the fictional s ...
in
Cape Town
Cape Town ( af, Kaapstad; , xh, iKapa) is one of South Africa's three capital cities, serving as the seat of the Parliament of South Africa. It is the legislative capital of the country, the oldest city in the country, and the second largest ...
,
South Africa
South Africa, officially the Republic of South Africa (RSA), is the southernmost country in Africa. It is bounded to the south by of coastline that stretch along the South Atlantic and Indian Oceans; to the north by the neighbouring countri ...
. It connects the northern suburbs (
Milnerton
Milnerton is a seaside suburb on Table Bay and is located north of central Cape Town in South Africa. It is located 11 kilometres to the north of the city's centre.
Suburbs
Suburbs/ neighbourhoods of the greater Milnerton area include:
* Bot ...
) to
Muizenberg
Muizenberg ( , Dutch for "mice mountain") is a beach-side town in the Western Cape, South Africa. It is situated where the shore of the Cape Peninsula curves round to the east on the False Bay coast. It is considered to be the main surfing spot i ...
in the south, and crosses both the
N1 and the
N2. For part of its length, from the N1 interchange to
Plumstead
Plumstead is an area in southeast London, within the Royal Borough of Greenwich, England. It is located east of Woolwich.
History
Until 1965, Plumstead was in the historic counties of England, historic county of Kent and the detail of mu ...
, it is a
limited-access freeway (
motorway
A controlled-access highway is a type of highway that has been designed for high-speed vehicular traffic, with all traffic flow—ingress and egress—regulated. Common English terms are freeway, motorway and expressway. Other similar terms i ...
). From Mowbray to Muizenberg, it is parallel to the
M4 Main Road.
Route
The M5 begins at the Potsdam interchange with the
N7 Highway in the suburb of
Dunoon
Dunoon (; gd, Dùn Omhain) is the main town on the Cowal peninsula in the south of Argyll and Bute, Scotland. It is located on the western shore of the upper Firth of Clyde, to the south of the Holy Loch and to the north of Innellan. As well ...
. It goes south-south-west as Potsdam Road and reaches a junction with the
M14 (Blaauwberg Road), where it becomes Koeberg Road and becomes a dual carriageway. The M14 joins the M5 for a few metres southwards before becoming its own road eastwards (Plattekloof Road) while the M5 continues south as Koeberg Road. It proceeds southwards for 9 kilometres, through the large suburb of
Milnerton
Milnerton is a seaside suburb on Table Bay and is located north of central Cape Town in South Africa. It is located 11 kilometres to the north of the city's centre.
Suburbs
Suburbs/ neighbourhoods of the greater Milnerton area include:
* Bot ...
, to reach the Koeberg Interchange with the
N1 Highway (Table Bay Boulevard) in
Brooklyn
Brooklyn () is a borough of New York City, coextensive with Kings County, in the U.S. state of New York. Kings County is the most populous county in the State of New York, and the second-most densely populated county in the United States, be ...
, where it becomes a
limited-access motorway.
It proceeds southwards from the N1 interchange as the Black River Parkway, through
Maitland
Maitland is an English and Scottish surname. It arrived in Britain after the Norman conquest of 1066. There are two theories about its source. It is either a nickname reference to "bad temper/disposition" (Old French, ''Maltalent''; Anglo Norm ...
, to reach an interchange with the
N2 Highway
The N2 is a national route in South Africa that runs from Cape Town through George, Gqeberha, East London, Mthatha and Durban to Ermelo. It is the main highway along the Indian Ocean coast of the country. Its current length of makes it ...
(Settlers Way), where it becomes the Kromboom Parkway. It proceeds southwards, through
Athlone
Athlone (; ) is a town on the border of County Roscommon and County Westmeath, Ireland. It is located on the River Shannon near the southern shore of Lough Ree. It is the second most populous town in the Midlands Region with a population of ...
,
Rondebosch East
Rondebosch East is a residential suburb of Cape Town, South Africa, about south-east of the city centre. As the name suggests, it is located to the east of the neighbouring suburb of Rondebosch. it had a population of approximately 4,600 people ...
and
Lansdowne Lansdowne or Lansdown may refer to:
People
* Lansdown Guilding (1797–1831), Saint Vincent and the Grenadines naturalist and engraver
*Fenwick Lansdowne (1937–2008), Canadian wildlife artist
* George Granville, 1st Baron Lansdowne (1666–1735) ...
, to reach the
M68 (Ottery Road) interchange in
Plumstead
Plumstead is an area in southeast London, within the Royal Borough of Greenwich, England. It is located east of Woolwich.
History
Until 1965, Plumstead was in the historic counties of England, historic county of Kent and the detail of mu ...
, where the M5 loses its
motorway
A controlled-access highway is a type of highway that has been designed for high-speed vehicular traffic, with all traffic flow—ingress and egress—regulated. Common English terms are freeway, motorway and expressway. Other similar terms i ...
status but remains a dual-carriageway as Prince George Drive. It proceeds southwards, through
Retreat, to enter
Muizenberg
Muizenberg ( , Dutch for "mice mountain") is a beach-side town in the Western Cape, South Africa. It is situated where the shore of the Cape Peninsula curves round to the east on the False Bay coast. It is considered to be the main surfing spot i ...
on the
False Bay
False Bay (Afrikaans ''Valsbaai'') is a body of water in the Atlantic Ocean between the mountainous Cape Peninsula and the Hottentots Holland Mountains in the extreme south-west of South Africa. The mouth of the bay faces south and is demarcat ...
Coast, where it terminates at a roundabout junction with the
R310 (Baden Powell Drive).
![Smash and Grab Hot Spot, Retreat (South Africa)](https://upload.wikimedia.org/wikipedia/commons/4/4f/Smash_and_Grab_Hot_Spot%2C_Retreat_%28South_Africa%29.jpg)
Koeberg interchange
The largest interchange on the M5 is the Koeberg interchange, connecting the M5 with the N1. The merging of lanes at this interchange used to result in multi-kilometer stop/start queues approaching the interchange on the M5.
Koeberg interchange elevated freeway upgrade
In 2008, work began to upgrade the Koeberg interchange with elevated freeways joining the M5 and the N1. The elevated freeway from the N1 onto the M5 was completed in June 2010 in time for the
2010 FIFA World Cup
, image = 2010 FIFA World Cup.svg
, size = 200px
, caption = ''Ke Nako. (Tswana and Sotho for "It's time") Celebrate Africa's Humanity'It's time. Celebrate Africa's Humanity'' (English)''Dis tyd. Vier Afrika se mensd ...
, while the other direction was completed in November 2011.
At the end of 2011, Google maps street view of this interchange showed the progress of the work on the interchange in stages by combining images over time and connecting them underneath existing bridges. This enables the viewer to experience a form of virtual reality during multiple points in the construction phase.
Design
The elevated freeways embody some innovative design features and principles. For example: The elevated freeways had to be built without disrupting the daily flow of some 200 000 vehicles. The existing roads and bridges had already used up the available land into which to expand. The intersection is hemmed in by a canal, railway reserve, power transformer, and industrial buildings etc. Thus the possibility of overlaying the existing structures with a bypass had to be envisioned. It had to be a system that could fit into the existing interchange. Oval reinforced concrete pillars with "T" pieces atop, standing on foundations supported by concrete piles, could fit into the spaces between existing roads and bridges. These could in turn support post-tensioned concrete "U" beam spans, cast on the ground and lifted into place by crane. The road deck would be cast on top of the "U" beams. Five beams between each "T" topped pillar allowing for a double lane road deck. The beams resting on each side of the "T" piece support, are connected to each other and the deck by a concrete end which resists lateral-flexing of the deck between-beams.
The roadway on both elevated freeways narrows from a double lane to a single lane at the point where it connects with the existing N1 and the M5 motorways. At this point, the elevated freeway presents the motorist with a down-hill slope to encourage acceleration. The elevated freeway feeds into its own lanes on both of these existing freeways allowing acceleration and preventing congestion.
"U" beam spans
The "U" beams would have sloping sides like a "V" with a flat bottom. The forces at the centre of the span cause lateral inward compression at the bottom of the "V" and lateral outward compression transmitted into the deck as tension. The longitudinal tension, at the bottom of the "V" and at the centre of the span, is absorbed by potent post tensioned cable embedded in the concrete. Each beam rests on its ends, on purpose designed steel plates, which accommodate expansion and contraction and transmit the weight of the span into the "T" pieces atop the oval pillars.
The roadway deck would extend beyond the edge of the outer beams and be lined with pre-cast crash barriers.
Box girder bridges
Box girder bridges were conceived, designed and built to span the railway reserve and the long stretches over the outbound N1 carriageway and the Northbound M5 carriageway as it approaches the N1. These had to be supported by scaffolding in the case of the end bridges and by "I-beam" steel trusses in the case of the railway reserve spans. The railway reserve also includes the height of the electrification services. This height added to the height of the "I-beam" steel trusses, the scaffolding on top of the trusses and the height of the box girder bridge is the determining factor in the extraordinary height of the new elevated freeway, which at its highest point is at the same height as the 5th story of the adjacent old mill building.
During construction of the end box girder bridges, the traffic had to be diverted round the supporting scaffolding. This was especially inconvenient on the outbound carriageway of the N1 where speed was severely reduced, adding heavily to congestion.
Construction
Where the roadway deck extended beyond the edge of the outer beams, this would be made possible by the use of wooden triangular supports temporarily bolted to the outer beams and covered with concrete shutter-boards. The beams themselves would have pre-cast holes to accommodate the bolts holding the triangles in place.
"U" beams
Each "U" beam, weighing 80 metric tonnes, would be cast on the ground at a nearby designated temporary factory area between the N1 and the railway reserve. Each beam would be a specific length and be designated to be placed in the exact place for which it was designed. The beams would be cast on a set of reusable foundations and steel moulding panels supported by steel jacks. The beams would be transported on the ground by a purpose built pair of 12 wheeled trucks, made of welded steel "I-beam" frames, each attached to the end of a concrete span "U" beam and then towed a short distance to the construction site by a conventional diesel mechanical horse.
Pillars
Each pillar and its "T" piece would be treated as a project in its own right. Purpose-built steel mouldings would be reused for each pillar and each pillar would be constructed in stages. The mouldings would be moved by cranes. Where the underlying ground was "soft", steel reinforced concrete piles would be driven into the base of the foundation hole and the upper protruding ends incorporated into the foundation.
Crash Barriers
The pre-cast crash barriers lining the edge of the deck would also be manufactured nearby using purpose made steel moulds. They would be bonded into place by having re-bar-steel loops protruding from both the edge of the road deck and also from the bottom of the barrier section. These loops would mate together when the barrier was placed and be affixed there by injecting concrete into the space between the deck and the barrier, permanently bonding the protruding loops together. Subsequently, a concrete guard rail would be cast on top of the crash barrier.
The Roadway deck
The deck would be constructed like any other reinforced concrete deck with the exception that the shuttering is designed to remain in place permanently and there is no use of scaffolding to support the shuttering. Pre-cast lip and groove formations on the upper edges of the "U" beams were designed to accommodate a thick Masonite type of shuttering board which would bear the weight of a man walking on them. The beams themselves provide a safe walk way for workers to access the section of road deck being constructed, during construction. When the steel reinforcing rod framework has been completed over the shuttering, a
ready-mix concrete
Ready-mix concrete (RMC) is concrete that is manufactured in a batch plant, according to each specific job requirement, then delivered to the job site "ready to use".
There are two types with the first being the barrel truck or in–transi ...
is pumped up from a mixer parked on the underlying roadways. This concrete is spread over the shuttering and reinforcing steel work and allowed to cure. Finally the deck is covered with a conventional asphalt macadamised tar and granite chip surface and marked with paint.
References
See also
Cape Town Government's view of the Koeberg InterchangeGovernment empowerment plan
{{DEFAULTSORT:M5 Road (Cape Town)
Roads in Cape Town
Highways in South Africa
Streets and roads of Cape Town
Metropolitan routes in Cape Town