 | WESTLINK M7 Arcing across Sydney’s west, the new M7 motorway, by Conybeare Morrison and Context, is the result of a successful collaboration between the disciplines of urban design, landscape design and engineering.
REVIEW Peter Mould
PHOTOGRAPHY Brett Boardman
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The Light Horse
Interchange, where
the M7 meets the M2
in Sydney’s west.
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Noise walls on the M7.
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The surrounding
parkland is visible
through transparent
noise screens on the
Hoxton Park viaduct.
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The 450-metre,
clear span bridge at Old
Windsor Road.
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Light
Horse Interchange.
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Internal view of a
shared path bridge over
a local road. Four
shared path bridges
cross the M7.
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The
40-kilometre shared
Westlink Cycleway and
Walking Path runs
through the open space
associated with the M7.
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The shared path
bridge crossing the M7
at Cecil Hills.
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Quakers Road bridge
over the M7, an example
of the coloured blade
walls, which clad the
piers of a number of
bridges.
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Part of the
artwork at the Light
Horse Interchange,
which represents a
parade of the light
horsemen of the First
World War. Wire
plumage mimics the
distinctive emu feathers
worn in the slouch hats
of the diggers.
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Illuminated pyramid
marker at the southern
end of the M7, where it
intersects with the M5.
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Since the early twentieth century, highways have
been a significant part of city and country
landscapes. If the city is the heart of a region, its
highways have been the dominant (overly so, some
may argue) arteries that fed the city and distributed
its products. They have occupied the minds of
planners and engineers and become major elements
in the urban landscape, connecting at a macro scale
and often severing at the micro.
Highways don’t present opportunities for
conventional urban form or space. Not here the
parvis before the cathedral or the park defined by
suburban development. This is space uncontained
by the density of built form, and it is that lack of
containment that gives expression to the sculptural
elements of large-scale engineering, which, at their
best, are the pure expression of structure.
In 1966 Lawrence Halprin wrote, “When
freeways have failed, it has been because their
designers have ignored their form-giving potentials
and their inherent qualities as works of art in the
city. They have been thought of only as traffic
carriers but, in fact, they are a new form of urban
sculpture for motion. To fulfil this aim freeways
must be designed by people with sensitivity to
structure but also to the environment; to the effect of
freeways on the form of the city; and to the
choreography of motion.”1
More recently there has been a preoccupation
with moving beyond structural expression and its
refinement and dealing with elements that accrue to
highways in their urban setting, or making bold
gestures at place making or place marking; City Link
Gateway in Melbourne and Craigieburn Bypass
being excellent examples.
In December 2005 the much-anticipated and
somewhat delayed Sydney Metropolitan Strategy
was released. In the same month, the M7 toll
motorway was opened ahead of schedule. Road
infrastructure, with its attendant federal seed
funding, has been steaming ahead of other transport
infrastructure (and strategic planning) in Sydney for
some time. The M7 features prominently in the
metro strategy as part of the primary road transport
matrix across the city. It serves as a major connector
to the newly proposed growth areas in the
north-west and south-west sectors of the city.
The M7 arcs for 40 kilometres around Sydney’s
suburban fringe and, barring the Lane Cove Tunnel,
completes the Sydney Orbital – a giant motorway
ringing the bulk of Sydney’s urban development and
linking the M2 in the north with the M5 in the
south. It provides a bypass to Sydney as part of the
inter-capital route system and includes a
40-kilometre grade-separated shared path with its
own bridges and lighting.
Deemed a success in engineering and transport
terms, the M7 has won major engineering awards,
was finished ahead of schedule, and has received
none of the negative press that has marked other
recent major road developments in Sydney: the M5
East – poorly sized; the M2 – poorly detailed; and
the Cross City Tunnel – poorly priced and marketed.
So what worked on the M7? It was, after all,
procured through a Public Private Partnership
process, which is generally perceived to sacrifice
quality for time and cost. But here we have a
roadway made of simple, well-designed and
executed elements in a consistent language for its
entire 40-kilometre length.
Its success starts with the brief. Design was
integrated in the bid and urban design was specified
alongside engineering, management and legal
requirements. The Roads and Traffic Authority
(RTA) set up an urban design evaluation team under
their senior urban designer, Raeburn Chapman, to
assess the urban design in the proposals, and this in
turn became the RTA’s design monitoring and
advisory panel for the project. Design became a
serious pursuit and was embraced by the entire
team, requiring commitment from the proponent
and their engineers as well as their urban design and
landscape team, Conybeare Morrison and Context.
The highway layout is the primary ordering
device for the urban elements that populate it. The
road passes through essentially flat urban and rural
settings, and alongside Western Sydney Parklands
for 27 kilometres of its length. The alignment has
been carefully planned to maximize opportunities
for views as well as creating smooth grades for safe
motoring, but, in an even topography, there are
few opportunities for the surprise vista at a turn
in the road or a landscape glimpse revealed from
the crest of a hill. Views are captured through
long intermittent panels of glass noise walls.
Other sections of road – so successful in
connecting motorists from one part of Sydney to
another – effectively disconnect users from the
surrounding suburbs.
Here, in place of landscape features, a suite of
urban elements and artworks mark occasions along
the journey. Refined structures provide a backdrop
to this mass transit corridor and to the kinetic
energy of the vehicle. Noise walls, toll gantries,
lighting and signage are of a consistently high
quality. The bridges bisecting the highway have
clean, simple spans – the piers, clad in colourful
blades extending beyond the deck, make a platform
for the light poles. The clear soffit, the continuous
parapet, the slightly sloping throw screens, and
the neatly resolved abutments provide a calm and
elegant series of structures, adding to the quality
of the journey.
These elements collectively demonstrate a
commitment to design and to a healthy collaboration
between engineer and urban designer – the
450-metre-long haunched road bridge crossing Old
Windsor Road being the most spectacular example.
The lighter, shared bridges across the road
corridor are less successful. Simple silver triangular
trusses are topped with a complicated canopy of
meshed screens. The screens’ geometry varies and
dilutes the strength of the structural form supporting
it. The overall impression is one of mismatched
elements: either the truss seems too heavy or the
throw screen too light and playful.
At its north end, the M7 morphs into the M2, but
the other two major intersections (the M4 and M5)
are marked with the necessary flyovers and exit
ramps, but also with major art installations. The
M4/M7 14-hectare interchange is dramatic,
super-scaled and surprisingly elegant. The geometry
of the post-tensioned box girders, the simplicity of
the piers and the slenderness of the sweeping curves
of the feeder ramps add a lightness that belies their
engineering achievement.
Named the Light Horse Interchange, the
intersection commemorates the regiments that
served in World War One. The centrepiece of the
installation is a 55-metre light pole and ranked along
the four medians that approach it are markers
representing soldiers on parade. These are coloured
the red of Flanders poppies, and wires bunched at
their crown symbolise the distinctive emu feathers
worn by the light horsemen in their slouch hats.
This is a strong theme for public art, but its
execution is disappointing. It is artwork seen in
passing, at speed, and calls for a robust scale so that
the rhythm of the parade is legible. The feathers, too,
are unconvincing.
The intersection with the M5 in the south is
marked with a 25-metre pyramid of earth from the
excavations. Here, the scale is right but the shaping
of the hill is too crude and the geometry imperfect,
so that its giant steel cap sits uncomfortably,
effective only as a night beacon. The night image
of the road corridor is, however, a great success,
with the major elements well lit to celebrate scale
and sculptural form.
The landscape design is a unifying element
establishing a character based on indigenous
vegetation communities. Colour in the planting is
used to highlight and reinforce the colour of the
structures, which are drawn from local references.
Sadly, the landscape philosophy is not yet fully
evident. The recent drought has caused about
30 percent failure of the planting so far and the
substantial planting programme has been held
back, awaiting more conducive weather conditions.
The M7 team has achieved a high-quality
outcome, sensitive to its sculptural form, to its
structure, to its place in the city and to its local
environment. The success comes from the
integration of the skills of the urban and landscape
designers with those of the road and bridge
engineers. Perhaps the ensemble would have had
greater success with the inclusion of a public artist.
PETER MOULD IS NSW GOVERNMENT ARCHITECT AND GENERAL
MANAGER OF THE NSW GOVERNMENT ARCHITECT'S OFFICE.
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FOOTNOTE
1. Lawrence Halprin, Freeways (Reinhold Publishing Corporation, New York, 1966).
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| WESTLINK M7 |
Urban design Conybeare
Morrison International
—project director Darrel
Conybeare; design
associate Colin
Polwarth. Landscape
design Context
Landscape Design—
project director Oi
Choong; design
associate Julia
Finlayson. Design and
construct Abigroup /
Leighton Joint Venture
(ALJV). Engineer
Maunsell / SMEC Joint
Venture (DJV). Lighting
design Webb Australia
Group. Acoustic design
Heggies Australia.
Traffic Management
Control Systems United
KG [formerly Alstom].
Tolling Transurban
Group. Owner Westlink
Motorway. Client Roads
and Traffic Authority
NSW (RTA).
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