FROM RESEARCH TO DESIGN
re-engineering the space of Trafalgar Square
Professor Bill Hillier, Tim
Stonor, Mark David Major and Natasa Spende
September 1998
Introduction
The Space Syntax Laboratory UCL is part of Sir Norman Foster's team
carrying out the World Squares for All project in the centre of London.
It advises the team on pedestrian space use and movement and spatial
design. In this paper, we describe how the Space Syntax team analysed
and modelled the existing pattern of space use and movement in and around
Trafalgar Square, and from this evolved proposals for design modifications
which would lead to a richer pattern of use there.
Aims of the Team in Trafalgar Square
The aims of the team in Trafalgar Square have been:
a. to make sure the space is accessible and intelligible to all pedestrians,
including people living and working in London, people visiting the National
Gallery, and tourist visitors
b. to make sure that all the space in the Square is used to some degree,
since large, empty spaces always detract from the 'feelgood' factor
in a public square
c. to ensure everyday use of the Square throughout the year by Londoners
and visitors, as well as ensuring it is safe for special occasions
d. to make sure there is enough space in the Square for all those who
would in future benefit from using it.
The Current Pattern of Space use and Movement in the Square
As part of its work on the World Squares for All Project, the Space
Syntax Laboratory has undertaken the most detailed survey ever of pedestrian
movement and space use in central London. The objective in making this
survey has been to establish the current pattern of pedestrian activity
in the study area, identify the specific problems faced by pedestrians
and, from this analysis, generate design ideas which address these problems
and satisfy the overall aims of the project.
In making the survey we have sent teams of trained observers onto the
streets of London. They have counted leveles of pedestrian movement
in over 300 locations at different times of the day, on different days
of the week, and in different seasons of the year (Figure 1).
Figure 1 Pedestrian Activity in Trafalgar Square
The results of our survey provide a comprehensive picture of pedestrian
activity and show that the key features of space use in Trafalgar Square
are:
a the heart of the Square is used almost exclusively by visitors (the
red dots in Figure 1)
visitors are concentrated mainly in the south-east corner of the Square,
leaving large, relatively empty areas to the north and west
b there is virtually no movement across the heart of the Square (the
thin blue lines in Figure 1). Instead we see Londoners moving around
the outside pavements of the Square (with some movement across the inside,
southern pavement) and visitors meandering slowly within the Square
c there is much 'informal' road crossing by visitors, especially from
the south side of Trafalgar Square in order to get to the best views
from the King Charles traffic island (the thick green lines in Figure
1)
d there is almost no stationary use of the Square by Londoners. Instead,
most Londoners walk around the edges of the Square than across it. In
doing so they face major delays at pedestrian crossings. Many cross
'illegally' when faced with the choice of waiting
e the upper level space on the north side of the Square is virtually
unused, either for movement or stationary activity.
Why the Square Works this Way
At first sight, the main problem of Trafalgar Square appears to be that
it is cut off from its surroundings by dense traffic. In fact, this
is only a part of the story. Simply removing the traffic would not in
itself lead to significant improvements in pedestrian use. Space Syntax
analysis of Trafalgar Square shows that - while the effects of traffic
are important - they are not nearly as important as the influence of
design.
Recent research has shown, and experience confirmed, that design can
make the difference between well and poorly used urban spaces, and that
design means first and foremost spatial design. Merely adding
landscaping and facilities to poorly designed spaces will not make those
spaces work. Good spatial design involves three key elements:
a. simple, direct routes for pedestrian movement which pass through
the middle of the space and not just around its edges
b. positions within the space from which people can see out in several
directions, and therefore understand the way in which the square fits
into its wider urban context
c. facilities for eating, drinking or resting which are located close
to - but not in the way of - the main pedestrian movement routes.
Our analysis shows that each of these elements is missing from the current
design of Trafalgar Square. Instead, the current design of the space
is directly responsible for the uneven pattern of use which we have
observed. In particular:
a. detailed analysis of the visual 'fields' available from Trafalgar
Square shows that the views available from the geometric centre of the
Square (Figure 2) are very constricted, and nowhere near as strategic
as those from the King Charles traffic island (Figure 3). This is why
visitors to London gravitate towards the traffic island - dashing across
the road with camera and guidebook in hand - in order to gain their
bearings and take photographs:
Figure 2 Visual Field from Geometric Centre of Trafalgar Square
Figure 3 Visual Field from King Charles Traffic Island
b. the existing stairs in the north-west and north-east corners of the
Square inhibit the kind of criss-crossing movement through the body
of the space which other studies have shown to be an essential characteristic
of well-used squares. As a result, Londoners moving from one corner
of Trafalgar Square to the other find it easier to walk around the edges
of the space than to cross diagonally.
Computer modelling of the spatial layout of the Square allows the precise
relationship between spatial design and pedestrian activity to be measured.
In Figure 4, the network of pedestrian routes in and around Trafalgar
Square has been analysed using Space Syntax software:
Figure 4 Space Syntax Computer Model of Trafalgar Square EXISTING
The software calculates the relative accessibility of each spatial
link in the network and represents the most accessible routes as red
lines, then orange, yellow and green, to the least accessible lines
which are blue. Accessibility is measured by calculating shortest journey
routes between each link and all of the others in the network (defining
'shortest' in terms of fewest changes of direction).
Visual and statistical comparison between the Space Syntax analysis
of accessibility and the actual pattern of pedestrian movement in Trafalgar
Square shows a high degree of correspondence. In fact, the computer
model successfully accounts for approximately three-quarters
of the actual movement pattern (Figure 5), doing so even before we consider
the effects of other environmental variables such as local land uses,
transport facilities, building heights, vehicle movements and population
densities:
Figure 5 Correspondence Between Computer Forecast and Actual Movement
Rates
In this way, Space Syntax analysis provides the design team with a powerful
tool for understanding the current pattern of pedestrian activity in
Trafalgar Square, and demonstrating how this pattern is directly related
to spatial design. Having understood current activity, the method can
then be used as a design tool, by simulating design changes and evaluating
the effects of these in terms of pedestrian activity.
Our experience from the World Squares for All project shows that Space
Syntax analysis is also a design generator, highlighting areas
which are either problematic (such as the change in level between the
upper and lower parts of the Square) or which offer significant design
potential (such as the area to the south of the Square around the statue
of King Charles). When the spatial characteristics of an area have been
pinned down, ideas for solutions begin to emerge in a process we term
"evidence based design".
From Research to Design: Re-engineering the Square
The findings of the Space Syntax analysis have generated a number of
key redesign ideas for Trafalgar Square. These have been tabled within
the team and evaluated alongside others over the course of the project.
Some of these are illustrated in Figure 6:
Figure 6 Proposed Redesign of Trafalgar Square
The redesign proposals include:
a. the southward extension of the Square and creation of new, direct
pedestrian crossings to the north-west corner of Whitehall and the north
side of Northumberland avenue. The main effects/benefits of this will
be:
b. to expand the area of the Square which will be naturally used by
visitors, decreasing the current congestion in the south-east corner;
c. to create an area in the Square with stunning all round views (in
contrast to the current restricted views) from which visitors will take
pictures both back into the Square and outwards into the surrounding
urban area
d. to make important views available for Londoners and visitors alike
to assist in orientation and movement. These include: Whitehall towards
the Palace of Westminster; the Mall towards Buckingham Palace; Northumberland
Street towards Hungerford Bridge and Cockspur Street towards St James'
e. to make the 'centre of London' a natural and safe destination for
visitors to London, thus increasing the prestige, significance and reputation
of the whole Square
f. opening up the north-east and north-west corner steps into the Square
by the creation of two new flights of steps on diagonal alignments.
The main effects/benefits of the 'diagonal' steps will be:
g. to facilitate movement across the Square for people living and working
in the area, so that the Square becomes a natural part of their everyday
journeys rather than the obstacle it is at present (currently the orientation
of the steps is a key factor in eliminating natural movement through
the Square), creating naturally used routes which are more pleasant,
quicker and less hazardous than the current difficult routes around
the outside
h. to facilitate movement by visitors to and from the southern parts
of the Square, allowing movement into these areas to approach from different
directions
i. improving the feel of the Square by creating background movement
across the Square in several directions - this being crucial to the
sense that a space is well and naturally used. This will help generate
stationary use within the Square by Londoners as well as visitors
j. renovation of the upper level space (between the National Gallery
and the existing Square) as an intrinsic part of Trafalgar Square.
The renovation of this space with its wonderful viewing potential will
require the elimination of all everyday traffic (allowing occasional
access for special visitors to the main entrance of the National Gallery)
from the north side of the Square. However, this on its own, while essential,
will not in itself realise the potential of the upper level space. This
will also require the careful design of this space and its relation
to the main body of the Square, since:
a. movement will continue to be primarily on the National Gallery side
of this space, and more generous provision will therefore have to be
made for this movement on the north side of the upper level space;
b. the south side of the upper level space will not (even with the corner
steps) be a significant movement space, but will offer wonderful opportunities
for stationary uses, for people wishing to relax and spend some time
in the Square
c. a direct link between the lower level body of the Square and upper
level part of the space via a new, centrally located stairway. At present
the north, lower level part of the Square and the upper level space
directly above it are the least used areas of the Square. While the
corner steps will create diagonal movement across the Square, they will
not by themselves animate either of these spaces. Nor will pedestrianisation
of the upper north level alone animate the south side of the upper space.
The central link between these two potentially poorly used spaces will
therefore be critical to their mutual animation by:
d. providing a direct route into the lower level body of the Square
from the National Gallery via the least used part of Trafalgar Square.
Visitors to the Gallery will use this stair whereas they would not necessarily
go into the Square if they had to use the corner steps. These steps
will create a more localised link which will allow 'drift' from one
space to the other, as well as providing a convenient route for people
going directly to and from the Gallery
e. creating a natural east-west division in the upper level space, with
more Londoner-focused facilities provided on the west side upper level
space (where people working in the area would naturally stop) and more
popular facilities on the east side of the upper level space (where
there will be a higher and more mixed local movement population)
f. and, in general, the creation of new, well used diagonal routes across
the Square for Londoners which are more pleasant, less time consuming
and less hazardous that the current tortuous routes around the edge
of Square.
Each of these design characteristics has emerged following numerous
'runs' of the pedestrian computer model. Since processing times are
very short (a matter of seconds) it has been possible to use the computer
as a sketchpad for testing, rejecting and refining design ideas. Analysis
of the redesign proposals indicates the extent to which pedestrian linkages
in and around the Square might be considerably improved (Figure 7).
Figure 7 Space Syntax Computer Model of Trafalgar Square PROPOSED
The Space Syntax model shows a significant increase in overall levels
of pedestrian accessibility. In particular, new diagonal routes can
be seen passing from one corner of the space to the other, making use
of the new corner stairs and bringing a significantly greater degree
of pedestrian activity to the heart of the space than exists at present.
SUMMARY
Space Syntax techniques have been used by the World Squares team to
generate and evaluate a range of design proposals throughout the Study
Area. In each case the needs of pedestrians have been carefully evaluated
through detailed observations of existing activity and spatial modelling
of design possibilities. In this way a masterplan for the area has been
developed which is firmly founded on the results of robust, evidence
based techniques.
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