Hi all, thought this article from New Scientist would be of interest to
some of you archis out there.


Well connected Understand how people use space and you can cut
crime,
construct buildings that foster creativity and
regenerate urban wastelands. Mick Hamer investigates a theory that
promises to take
the guesswork out of design.
By MICK HAMER
So there you are, waiting to cross the road when a car pulls up, a
passenger leans out and asks you the way to the nearest bank. There happen
to be two routes, a long drive down the main road with a single left turn
and a much shorter way that twists and turns through backstreets. Which do
you tell them?
The answer is the longer, simpler route. Try giving directions with too
many left and right-hand turns and the travellers are likely to end up lost.
Perhaps because our brains can cope with only so much complexity, humans
prefer easy routes over labyrinthine ones. It is the same desire for
simplicity that underpins the old music hall joke. 'How do I get to the Old
Kent Road from here?' runs the gag. 'Well if I were you,' comes the reply,
'I wouldn't start from here.'
Our preference for straightforward journeys may seem obvious, but it's
something that many architects and planners have missed. Not so Bill
Hillier, who first noticed it in the early 1980s while trying to fathom why
some buildings 'work' as places that promote creativity and communication.
But then to Hillier, who is professor of architecture at University College
London (UCL), roads and corridors are one and the same: spaces.  Roads are
spaces that link buildings; corridors are spaces that link desks with
photocopiers, faxes and coffee machines. 'People use space intuitively,
much like they use grammar,' he says. And just like grammar, space has its
own rules, which we use without thinking when moving from one place to
another.
Those rules, which stem from people's preference for easy journeys, are the
basis of a theory that Hillier calls space syntax. The theory challenges
established design practice and is couched in difficult terminology-factors
that have tended to stop it spreading quickly. But there is growing
evidence of its effectiveness. Wielding Hillier's ideas, researchers at
UCL's Space Syntax Laboratory can explain, for example, how cities grow and
why shops thrive in particular areas. Space syntax even helps
archaeologists to deduce the organisation of ancient societies from the
ruins of their buildings (see 'Ancient space', p 33).
But the real power of the theory is that it provides a way to design spaces
that work. Architects have used space syntax to design offices that foster
creativity, revitalise urban wastelands, and even make houses less likely
to being burgled. Recent research also shows that space syntax is a more
accurate way of forecasting traffic than the costly surveys used today.
Hillier's contention is not just that how spaces are connected determines
how much they will be used, but that this relationship is mathematically
predictable. 'If you design something in a particular way it will influence
people's movement, and you can predict when people will be in the same
space,' he says.
Hillier's analysis is topological-it focuses on the way elements in a
network are linked. Going back to the lost travellers, it is easier to
direct them to some roads than to others. It depends on how the roads are
connected. Hillier brings out the accessibility of roads-or lack of it-in a
more formal way. He and his colleagues catalogue routes between each road
and every other road in a network by the number of turns that must be made
to travel between them. One way to depict this is to draw up a stylised
line graph for each road (see Diagram, p 32). When these are combined using
the lab's computer model, they reveal a hierarchy that reflects how
accessible every road is from all other roads (see Maps, facing).  One of
the Space Syntax Laboratory's case studies is the road network of inner
London. Oxford Street, which runs east to west through the city, is the
road with the best links to the rest of the network. 'On average,' says
Hillier's colleague Alan Penn, 'you only need to turn left or right nine
times to reach anywhere in inner London from Oxford Street. On the other
hand, if you start from a back street in west London, you'll have to turn
twenty times or more.' In the completed analysis of inner London, Oxford
Street is at the top of the accessibility hierarchy while back streets are
at the bottom.
Two important consequences flow from these hierarchies. First, researchers
can forecast how much traffic will use a road from its position in the
hierarchy. Secondly, they can forecast which roads will be attractive
locations for offices and shops.
The conventional method of forecasting traffic is based on a loose analogy
with Newton's law of gravity, in which the attraction between two bodies is
proportional to their masses and inversely proportional to the square of
the distance between them. In the traffic engineers' version, the amount of
travel between any two zones within a wider area will be proportional to
the number of vehicles that start and end their journeys in each zone and
inversely proportional to the time it takes to travel between the zones. If
the engineers plan to build a fast new road, the model forecasts that the
new road will capture traffic from slower roads linking the zones.
To gather data for this model, engineers carry out a hugely expensive
survey of drivers, asking them where they have come from and where they are
going to. From this, they estimate how much traffic each zone generates.
They add a few fudge factors to make sure the model agrees with recorded
data, factor in the quicker journeys the new road will provide, and then
run the calculation to forecast levels of traffic at some time in the
future. The technique is notoriously unreliable in urban areas.
'Conventional models are absolutely dire,' says Phil Goodwin, professor of
public transport policy at UCL and the British government's adviser on
transport.  Penn and his colleagues found a strong correlation between a
road's position in the hierarchy combined with its width, and the volume of
traffic running along it. In research published last year, they show that
this method can account for more than 80 per cent of the variation in
traffic flows from street to street. The results are impressive compared
with conventional methods. An official audit of the government's forecasts
in 1995 found that half of them were wrong by more than 20 per cent.  Space
syntax also helps to explain why traffic can vanish when a road closes.
Traffic engineers normally argue that if you close a road, you need to
create a relief road to take the displaced traffic. But a study carried out
last year by Goodwin challenged this wisdom. It looked at a number of roads
that had been closed and found that a substantial chunk of traffic simply
evaporated. In practice, drivers have a lot of flexibility: instead of
driving to work, for example, they may work at home one day a week. Penn
says this is exactly the sort of result you would expect from space syntax.
If you sever a link in a network, a number of roads will become more
difficult to get to. They slip down the hierarchy, so the volume of traffic
on them will fall.
One of the beauties of the technique for modelling traffic flow is that it
works as well for pavements as for roads. From detailed surveys of
pedestrians, UCL researchers have found they can predict pedestrian
movement from the street pattern.
The logic behind these traffic patterns is crucial for understanding how
cities grow, and Hillier's ideas provide a way to predict this process and
perhaps to avoid creating urban wastelands. According to space syntax, a
road that can be easily reached-on foot or by car-will tend to be busy.
This offers shopkeepers and office developers a golden opportunity.
'Passing trade makes all the difference to whether shops are let or not,'
says Brian Raggett of the Royal Town Planning Institute in London.
Penn quotes the estate agent's adage: 'There are only three
things that
matter: location, location and location.' A prime location, says
Penn, has a
multiplier effect. At the turn of the century, Oxford Street was
already one
of the most accessible roads in London. In 1906, Gordon
Selfridge, an
American shopkeeper, started building the department store that
still bears
his name. The store rapidly became a destination in its own
right, adding to
the street's attraction. Other stores followed in its wake,
attracting still
more people to the street. Today many of London's department
stores are
still located on Oxford Street.
Merchants of Venice
The accessibility of spaces also gives a clue to how car-free Venice has
developed. The city's labyrinthine map of streets and alleys appears on
Hillier's computer. As on other Space Syntax Laboratory maps, the hierarchy
is coloured: red for the most accessible streets and blue for the least
accessible. Glaring out in red is the Rialto bridge over the Grand Canal,
which is where for centuries the merchants of Venice have plied their trade.
Then there's Berlin. After the Second World War, when East Germany built
the wall that cut the city in two, the old commercial district on
Friedrichstrasse, was cut off in the eastern zone. It could not be reached
from the west and in the east it was a backwater. Berlin grew two new
office centres. In East Berlin, the centre moved to the east. In West
Berlin, a new commercial centre flourished on Kufurstendamm.  Then, ten
years ago, the wall came down. Conventional models of urban development
predicted that the stronger of the two centres-presumably
Kufurstendamm-would come to dominate the city and the other would fade away.
But Jake Desyllas of UCL uncovered a different outcome. Sure enough, the
eastern centre faded, but office rents also dropped in Kufurstendamm. The
smart money has moved back to Friedrichstrasse. Its accessible location in
the city with its reunified road network makes it the prime site for
commercial development-just as space syntax predicts.  Penn contrasts the
way the multiplier effect has worked in Oxford Street with the way its
absence has created the wasteland of London's South Bank.
The South Bank was designed after the Second World War to be the cultural
centre of London. It has concert halls, theatres, a museum, an art gallery
and office blocks. But despite all this, the area has never attracted many
shops.
Among the reasons for this is that the planners segregated pedestrians and
vehicles-to cut accidents and prevent pedestrians holding up the traffic.
This left cars at ground level and condemned people to windswept walkways
above, and has kept the volume of people passing potential shopping sites
too low to make it worth building shops. 'The area was used by residents,
office workers, cultural audiences and general visitors. But there was
little mixing. They all used it at different times and used different
routes,' says Mike McCart, commercial director of the South Bank Centre,
which commissioned the Space Syntax Laboratory to analyse pedestrian
movement. 'The result was places that felt unsafe and hostile.' The lab's
plan for redeveloping the site includes removing some walkways to make the
layout of the area easier to understand, and to allow more mixing between
pedestrians and vehicles. The changes are intended to increase passing
trade and kick-start retail development. Penn predicts that once one shop
opens, it will rapidly attract others.  The space syntax researchers have
used the same techniques to redesign offices-starting with advertising
agencies. In these hives of creativity, the most productive offices are
those where the workers talk to each other.
Research from the Massachusetts Institute of Technology has shown that
about 80 per cent of seemingly casual conversations are about work.  So, in
one office, UCL researchers installed video cameras to monitor how people
used the spaces. They found that conversations happened largely by chance.
To increase the chances of these accidental encounters, they positioned
desks in an open-plan office so that most workers sat close to the main
through-route. The result was a large increase in conversations-which, says
Penn, helped to stimulate the creative spark. The lab also designed the
Coventry headquarters of Powergen, one of Britain's electricity generators.
The rate of chance conversations in the building increased by 9 per cent.
'It works very well indeed,' says a company spokesman. 'You bump into a lot
of people informally and you can sit down at special spare tables for a
brief meeting.' One of the most controversial predictions of space syntax
is that crime can be designed out of housing estates. In Britain, the 1970s
saw a major effort to pull down tower blocks and replace them with houses.
To make the new estates child-friendly, planners tried to exclude speeding
cars and passing strangers by designing them without through-routes for
cars or pedestrians.
But these designs had an unexpected side effect. Space syntax research on
housing estates in England revealed a direct link between the layout of
estates and burglaries. Houses in cul-de-sacs are far more likely to be
burgled than those on through-routes.
Hillier's computer plots the laboratory's analysis of one such housing
estate. As normal, through-routes show up red, while alleyways and
cul-de-sacs are blue. Then the computer shows the sites of burglaries.
Almost without exception, the burglar got into the house from one of the
blue spaces. 'What would you do if you were a burglar?' asks Hillier.
'Break a window that's visible from a through road or choose one that's not
overlooked?'
Hillier's solution-which flies in the face of established thinking-is to
avoid designs that create zones without fewer people or less traffic. The
threat of road accidents can be reduced by slowing traffic with devices
such as road humps. 'We now know a lot about how to calm traffic,' he says.
After twenty years, space syntax is starting to be widely used.  'It's
taking off,' says Hillier. It has a growing international following, and
local councils in Britain are increasingly asking the lab for help. If you
want to steer urban design, you have to understand how the system works
before you intervene, says Hillier. 'It's evidence-based design and
planning, rather like you have evidence-based medicine,' he says. The
patients just happen to be made of stone and concrete, rather than flesh
and blood.
          *          *          *
Further reading: Space is the Machine by Bill Hillier (Cambridge University
Press, 1996). The original theory of space syntax is laid out in The Social
Logic of Space by Bill Hillier and Juliette Hanson (Cambridge University
Press, 1984)
More information about space syntax and its uses can be found at
www.
bartlett. ucl. ac. uk/spacesyntax/
          *          *          *
Ancient space
The ruins of multistorey buildings in Chaco Canyon, New Mexico, have long
puzzled archaeologists. These once grand buildings are about a thousand
years old. But how were they used and by what sort of a civilisation? The
theory of space syntax is helping to answer some of the puzzles.  By
studying how the rooms in the buildings are connected, it's possible to
build a hierarchy showing which rooms were easily reached and which not.
This analysis can then be used to back up or contradict conclusions reached
from other reasoning. 'We use space in the same way today,' says Wendy
Bustard, curator of the US National Park Service's Chaco Canyon collection.
Archaeologists have found grinding stones in some of the rooms, which the
inhabitants used to make flour from corn. Conventional archaeology
concentrates on what rooms were used for. By analysing how these rooms
connected to others, Bustard deduced that the grinding stones were communal
and shared by several families. The inhabitants, it seems, had a highly
organised social structure. 'This implies a level of social organisation
above the nuclear family,' she says.
What makes space syntax a useful tool, says Bustard, is that it is a
'completely different' approach to archaeology. Of course, it does have its
limitations. Because ruins are incomplete, archaeologists have to make
assumptions to plug the gaps. Consequently, interpretations are often
hedged around with ifs and buts. 'That,' she says, 'is true in any kind of
archaeological analysis.'
New Scientist
Volume  164.   Issue   2212.
Copyright Business Monitor International Limited 1998
 

Adrian

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