Thames Gateway Bridge
Rebuttal to Simon Wolff Charitable Foundation
Proof of Evidence
TFL/REB/2065/1
TABLE OF CONTENTS
1 INTRODUCTION ...........................................................................................3
2 THE REALITY CHECK – ARCHWAY AND OXLEAS WOOD ......................5
3 ACCESSIBILITY AND EMPLOYMENT.........................................................6
4 PACKAGE OF MEASURES........................................................................11
5 IMPACT OF CROSSRAIL. ..........................................................................12
6 THE REST OF ROSEWELL’S ARGUMENT...............................................13
7 SUMMARY ..................................................................................................19
8 CONCLUSION.............................................................................................21
9 ANNEX 1 .....................................................................................................22
TFL/REB/2065/1 2
1 Introduction
1.1 This rebuttal to the George Stern proof of evidence has primarily been
prepared by Professor Rosewell with help and support from colleagues at
Transport for London and the GLA. The rebuttal uses the headings and
paragraph numbers of Mr. Stern’s proof of evidence.
1.2 There are two central elements to Mr Stern’s argument:
• That the analysis shows that accessibility worsens employment prospects
rather than improving them
• That a ‘reality check’ shows that people would not live near a bridge
1.3 This argument helpfully highlights the fact that successful regeneration of
the area will have two aspects, as detailed in the following paragraphs.
1.4 First, addressing the disadvantage suffered by existing residents and
communities in the area around the TGB. As the Regeneration Statement
(D822) has shown, and witnesses like Dr Gray have reinforced, this area
has suffered persistent problems of multiple deprivation. These include low
incomes, low employment levels, high unemployment, poor educational
standards, health, housing and access to services (the factors measured by
the Index of Multiple Deprivation). These factors interact in complex ways;
each in turn has complex causes – tackling barriers to employment, for
example, requires addressing issues like access to affordable childcare, the
workings of the housing market, the existence of benefits traps and
discrimination as well as ensuring people can physically access jobs. Mr
Stern criticises Professor Rosewell for not demonstrating that accessibility
is the primary cause of poor employment performance and that tackling this
will have some direct, immediate and quantifiable effect. He suggests that if
TFL/REB/2065/1 3
it cannot explain everything, it explains nothing. The reality is that these
problems are not amenable to simple solutions (if they were, they would
have been resolved by now). All it is possible to do is to identify the
relationship between accessibility and an area’s employment potential and
therefore to highlight what could be possible if the Bridge were to be
provided, and the range of other issues highlighted above were to be
addressed. That is what Professor Rosewell’s analysis seeks to do. One
thing is certain, however – addressing childcare, skills or any of the other
questions mentioned earlier will be of little consequence if those involved
cannot physically reach jobs, either in the immediate area or further afield.
Mr Stern (and indeed none of the other objectors that have appeared before
the inquiry) have not shown that it is possible to improve the economic
prospects of an area by making it less accessible and the fact that this area
has suffered both persistently poor accessibility and high levels of
deprivation provides a suggestive counterfactual.
1.5 The second aspect is encouraging new people and enterprises to move
into, and invest in, the area. This will support the development and
regeneration of the area, and help build the kind of new urban quarter
envisaged in the London Plan (D620). This in turn will help increase the
skills and income levels in the area and provide a wider range of
opportunities and facilities for existing residents. The evidence submitted by
London First shows the importance that developers and potential investors
ascribe to the Bridge and the improved accessibility it will bring; far from
bearing out Mr Stern’s strictures about the Bridge being likely to blight
development, this supports the view that it is essential to it.
1.6 This rebuttal is structured around the sections of Mr Stern’s proof in
dealing with these points.
TFL/REB/2065/1 4
2 The Reality Check – Archway and Oxleas Wood
2.1 Sections 2 and 3 of Mr Stern’s proof argue that the outcome of the
Archway road proposal and the existence of previous proposals in Oxleas
show that roads create slums. He suggests that the Archway is now a
pleasant area although it was long blighted – largely of course by the
failure to resolve the issue one way or another for a long period. Others
have dealt in detail with the proposition that the TGB ‘inevitably’ leads to
the destruction of Oxleas Wood.
2.2 The Archway example is a false analogy. The road proposal that he
mentions was intended as part of a strategic, high capacity motorway
network for London as a whole, and was not intended to support the
regeneration of the Archway area. The Thames Gateway Bridge is
explicitly designed to provide a local link to help support the development
and regeneration of the Thames Gateway area. Unlike the Archway
proposal, it incorporates dedicated public transport facilities. The
existence of tolling arrangements to minimise use for longer distance
through traffic is another difference.
2.3 He also asserts that no one would live near a road bridge over the
Thames. Yet there is considerable evidence to suggest that if suitable
housing is available, then people certainly do. There is considerable high
priced housing in the vicinity of many of London’s bridges, including
Putney, Wandsworth, Battersea, and Hammersmith.
2.4 As the evidence submitted by Stuart Robinson on behalf of London First
shows, there is considerable interest by major developers in making
significant investments in residential and commercial development in the
area immediately around the proposed Thames Gateway Bridge. It is
unlikely that this would be the case if there were a real prospect of the
Bridge having the kind of impact Mr Stern asserts. In fact, London First’s
TFL/REB/2065/1 5
evidence suggests that the area’s real potential is being held back by the
lack of transport infrastructure, including the Bridge.
2.5 The Mayor has consistently made clear that the Thames Gateway Bridge
is intended to support local development and regeneration, and will not
form part of London’s inter-regional strategic road network by being linked
directly to the A2 through Oxleas Wood. Indeed, he directed Transport for
London to dispose of the properties acquired for this purpose for the
former East London River Crossing. The regeneration case put before the
inquiry is based on this assumption; none of the benefits identified depend
on linking the Bridge to the A2 through Oxleas Wood.
2.6 It is further noteworthy that Mr Stern does not address the arguments for
housing and population potential created by the Bridge, and instead
focuses only on employment. As Professor Whitelegg argued in his proof,
there is much more to regeneration than simply providing new jobs, and
we have argued that population increases are a key part of the
regeneration potential of the TGB (see Table 2.2 of TfL/76).
3 Accessibility and employment
3.1 In Section 4 Mr Stern suggests that the core argument in Professor
Rosewell’s proof (TfL/Proof/05/2) is that accessibility is poor, and so are
facilities, while employment rates are also low. This is indeed a description
of the current state of affairs, although it does not describe the core analysis
which has been undertaken to establish the extent to which the TGB might
relieve these problems. The use of the word ‘if’ to which Mr Stern objects
simply refers to a calculation of the scale of local need.
3.2 As a way of scaling the challenge (or sizing it to use Mr Stern’s
terminology), the ‘if’ statement uses a calculation to show how many more
TFL/REB/2065/1 6
jobs there would be if employment were at the same levels as in Western
boroughs. This calculation is an illustration, not the ‘thrust of the argument’.
3.3 In paragraph 4.4, Mr Stern asserts that there is no disparity in health care
provision between east and west London boroughs by adding together
hospital and medical practice activities. The figures he presents show there
are over forty per million fewer primary medical practice activities in eastern
boroughs than in western; the balance is only made up because there are
around 37 per million more hospital activities in eastern boroughs than
western. Given that health policy is to move away from hospital to primary
care, and the disparity in health outcomes between east and west (in 2000,
male life expectancy in Newham was the lowest in London; nearly four
years less than that in Richmond), the situation does not appear to be as
positive as Mr Stern asserts. The larger figure for hospital activities in East
London may also suggest use of hospitals to make up for lack of medical
practice facilities; it also raises the question whether it would be possible to
plan more rationally for health provision given the additional accessibility
the Bridge will bring. Certainly, in West London it is easier for people on
either side of the Thames to access medical facilities on the other side; this
option does not exist for people in this part of East London.
3.4 By supporting the growth of local population, and supporting the
development of new, sustainable, communities the Bridge will help ensure
that new medical facilities will be provided. It will also enable health
planners to ensure the most efficient use is made of the facilities that do
exist at present. As mentioned in the Interregional Planning Statement
(2004) (TfL/20 paragraph 5.3), “Meeting the demands of both improvement
in services and of growth will have major implications for health care. As an
example of the necessary co-ordination of planning and service provision,
the two Strategic Health Authorities in the London part of the Gateway (i.e.
the NE and SE London Strategic Health Authorities) have made a
TFL/REB/2065/1 7
systematic assessment of healthcare needs up to 2016, including capital
and revenue costs.”
3.5 Mr Stern seems to believe both that services are in fact adequate while the
TGB will cost £2bn (2065 SWCF Proof Paragraph 4.4). It is not clear how
he reaches either conclusion. The total construction cost estimates for the
TGB is £378 million (TfL/Proof/03/2 paragraph 8.1.4), and the total project
funding requirement up to the end of construction of the bridge is estimated
to be around £641 million (in nominal terms) (TfL/Proof/06/2 paragraph
3.1.4).
3.6 In Section 5.1 and 5.2 Mr Stern discusses the comparison of 5 boroughs in
the East and the West at some length as if these are the basis of the
analytical results. This is not the case. The analysis is based on a
comparison of all the wards in London. The tables included in Professor
Rosewell’s Proof of Evidence (TfL/Proof/05/2) provide some illustrative
comparisons of averages for this small selection of boroughs. These
comparisons were included to try and bring to life some of the differences
between east and west London. They are not presented as the basis of the
statistical argument nor can they be used as such.
3.7 Such a small sample cannot be used to provide valid statistical tests of
difference and this is not how it has been used in the evidence.
3.8 Since there are only 10 boroughs in this small selection (and the boroughs
were selected because the analysis is considering the actual situation in
London, not a hypothetical case in which there is an unrestricted range of
places to consider), it is not at all surprising that differences are not found to
be significant. If, however, we perform an analysis of the data for all the
wards in the boroughs, the probability that accessibility in the two cases is
the same becomes extremely small at 0.0001. In other words, there is a
TFL/REB/2065/1 8
99.999 per cent probability that the level of accessibility in these western
boroughs is higher than in the eastern ones.
3.9 One of the reasons is that each borough has a variety of levels of
accessibility within it. He particularly cites the examples of Richmond-upon-
Thames (western and low accessibility) and Newham (eastern and high
accessibility). Richmond’s apparently low accessibility is due to the fact
that it has large areas of open space (Richmond Park at 1,000 hectares is
about one-sixth of the total land area of the Borough); the areas with high
population and employment density (such as Richmond itself and
Twickenham) enjoy high levels of accessibility. Similarly, in Newham the
northern part, around Stratford, enjoy high levels of accessibility and this
skews the figure for the Borough as a whole. Once these distortions are
recognised and allowed for, Mr Stern’s point becomes far less striking.
3.10 Mr Stern also conducts a correlation analysis of these boroughs in 5.2.
Again, this is a partial exercise which cannot be expected with this small
sample size to provide a reliable conclusion.
3.11 Mr Stern’s second table seeks to show that high accessibility “equals” a
high level of residents claiming Job Seekers Allowance (JSA). Again, the
results are distorted by taking boroughs as the spatial framework for
analysis. It focuses on only one element of the index of multiple deprivation
(which also covers income, employment, education, health, housing and
access to services), and the result Mr Stern highlights – that some inner
western boroughs show relatively high levels of JSA claims – is largely due
to the presence of high levels of unemployment in inner London (for a range
of reasons, including lack of affordable childcare, existence of benefit traps,
the housing market and longstanding problems of discrimination), where the
radial nature of the city’s transport network also means that there is high
TFL/REB/2065/1 9
accessibility. In any event, it is not the promoters’ case that a high level of
accessibility “equals” low unemployment, rather that tackling problems of
unemployment is extremely difficult without adequate accessibility
accompanied by necessary complementary measures.
3.12 Mr Stern has therefore set up a straw man which he then demolishes. This
does not in any way provide a refutation of the analysis which has been
developed to establish the role that accessibility has in supporting economic
performance.
3.13 In paragraph 5.4 Mr Stern suggests that the TGB does not make a
significant difference to accessibility in East London. He states that he has
already shown that a difference of 12 is not significant and TGB (without
Crossrail) only makes a difference of 6 points. This not a valid procedure
even on Mr Stern’s own terms. His original test looks at the probability that
two sets of data (in this case the two groups of boroughs) can be
considered to be significantly different. He concludes in section 5.1.7 that
the differences between them are not large enough to be able to draw this
conclusion.
3.14 However, testing the impact of the TGB on accessibility on one set of
boroughs only, i.e. the eastern set of boroughs, requires a different
statistical test. A suitable test for significance that we can use in this
instance is known as the paired t-test. As we are looking at a before-and-
after scenario on an identical set of areas, using the same index, this test is
entirely appropriate. This test is not to be confused with the basic t-test,
which is used to compare sets of values that cannot be paired, for example
when comparing boroughs in the East with boroughs in the West.
3.15 The paired t-test works by looking at the set of differences between the
paired values, and calculating how likely that the average of this set is equal
TFL/REB/2065/1 10
to zero. Comparing the average accessibility of the five boroughs in East
for 2016, with and without the TGB in place (assuming that Crossrail has
not been built) we have a set of positive differences equal to 5, 9, 7, 3 and
4. As all five of these differences are positive, casual observation would
suggest that there is a slim chance that the average of the values is equal
to zero. This is confirmed by the paired t-test which shows that the
difference is significant at the most demanding level1.
4 Package of measures
4.1 Mr Stern’s approach to accessibility is purely quantitative. He does not
address the different roles that each mode makes to development and
regeneration – access by road over the Bridge is not the same as access
by train via Crossrail or by other forms of public transport. This point is
particularly relevant when delivery of goods and services is considered.
Goods vehicles comprise 20% of peak hour TGB flows and 21% in the
inter-peak (Table 10 of TfL/Proof/04/5). This is one of the primary reasons
1
The paired t-test can be defined in the following way. Given two paired sets Xi
and of Yi measured on n values, the paired t-test determines whether they differ
from each other in a significant way under the assumptions that the paired
differences are independent and identically normally distributed. The test
statistic t is defined as:
n(n − 1)
t = (X −Y ) n
ˆ
∑(X ˆ
− Yi ) 2
i
i =1
ˆ ˆ
where X i = ( X i − X ) and Yi = (Yi − Y ) . This test statistic has (n -1) degrees of
freedom.
Our data returns a t-value of 5.20 of 4 degrees of freedom. Examining what is
known as the Student’s t-distribution we find that the probability of observing a t-
value this large, or greater, is equal to 0.0065. In other words, there is less than
a 1% chance that there is no difference in average accessibility through the
introduction of the Thames Gateway Bridge.
TFL/REB/2065/1 11
why it is only sensible to consider the Bridge as part of a package of
transport proposals to support development of the Thames Gateway area.
4.2 It is not clear what point Mr Stern is trying to make in 5.5.1. Mystagogy is
defined as a process of settling into the Church post Baptism, which Is not
very helpful. TfL regards the package of measures as important and not a
distraction.
4.3 The analysis presented in the Regeneration Statement (D822) and
Professor Rosewell’s proof (TfL/Proof/05/2) shows that there is a
relationship between accessibility and employment and population
potential. It also suggests as do all other sensible analysis that other
policies will be needed to realise that potential. The ‘package of measures’
outlines the other policies in place to show that there is some likelihood that
potential can in fact be realised.
5 Impact of Crossrail.
5.1 Crossrail is indeed important and in the annex to TfL/76, Professor
Rosewell has calculated in potential employment and population impact
(with and without TGB). Crossrail but it is also different from the TGB and
provides different benefits. For Bexley in particular both are needed, as
shown by Table 2.1 and the annex to TfL/76. These are different not
alternative investments. Moreover, Crossrail in orders of magnitude is more
expensive and therefore its benefits also need to be greater to justify it.
5.2 In paragraph 5.5.2 of his proof, Mr Stern appears to be advocating
changing the investment priority within London from east to west. Such an
approach would mean a wholesale change to the strategy outlined in the
London Plan (D620), which has been adopted following an exhaustive
examination in public. This, of course, is based around accommodating job
and population growth within London’s existing boundaries without
TFL/REB/2065/1 12
encroaching either on the Green belt or London’s open spaces. This can
only be achieved if efficient use is made of the city’s land resources
available and east London is made the priority area for new development,
regeneration and investment. A switch of investment of the kind advocated
by Mr Stern would mean consideration would have to be given to less
sustainable options for dealing with London’s growth.
6 The rest of Rosewell’s Argument
6.1 In paragraphs 5.6.1 to 5.6.9, Mr Stern suggests that Professor Rosewell
makes the argument that the TGB is intended to create a catchment area
which will make possible a high wage high productivity economy similar to
that in central London. This is a miss reading of Professor Rosewell’s Proof
(TfL/Proof/05/2) Section 5.1 to 5.5. These parts of her proof firstly illustrate
the change in accessibility that the TGB brings and then whether there is
any site availability to support regeneration. Mr Stern appears to accept the
contention here that neither sites nor infrastructure alone are enough to
create jobs.
6.2 Section 5.5 of Professor Rosewell’s Proof (TfL/Proof/05/2) addresses the
general contention that there is a need in London for more and better
infrastructure. This section cites a number of pieces of analysis, but makes
no assertion that this analysis has direct application to the TGB. It is
therefore incorrect to say as Mr Stern does in 5.6.9, that there are missing
links in the argument here: rather the section aims to establish that it is
worth examining whether such links exist. In her 5.5.4, Professor Rosewell
begins to report on the analysis which was undertaken directly of this
matter.
6.3 In paragraph 5.6.10 of his proof, Mr Stern suggests that Professor Rosewell
has accepted that there is no link between population density and
TFL/REB/2065/1 13
accessibility. This is based on a selective quotation from Professor
Rosewell’s proof; paragraph 5.5.3 reads in full:
“The study also looked at the relationship between population
density and accessibility. This shows that population density
increases with the number of jobs that can be accessed. However,
the relationship is not as strong as in the case of employment and it
reaches a peak at around access to 2 million jobs. As access
increases further, population density does not rise on average. (see
figure E3). The report concluded that ‘accessibility plays some role
in explaining or enabling higher population density but it is clearly
only one of several important factors”
6.4 Mr Stern deals with the results of the analysis of the impact of the TGB in
paragraphs 5.6.11 to 5.7.5. It would appear that he has not noticed that
these results are based on the analysis reported in the Regeneration
Statement (D822), although this is specifically stated in Professor
Rosewell’s 5.5.4. He therefore suggests that the results are contingent on
the inclusion of the City of London, although this is not the case and this
area is excluded from the analysis. Moreover, Professor Rosewell has
explained that the potential influence of central London is moderated in her
results, with the constrained scenario excluding it altogether and the
adjusted scenario providing an estimate midway between the result
including central London and one which excludes it (Technical Appendix to
the Regeneration Statement (D822)).
6.5 Mr Stern appears to attack Professor Rosewell for ‘admitting’ that there is
no perfect model and that causation is not easy to establish. He concludes
that no conclusion can therefore be drawn. However, he himself concludes,
on the basis of a simple analysis of only 10 boroughs, that transport
infrastructure has no effect on employment. If he wishes to argue that a
detailed and careful analysis cannot draw conclusions, then this applies still
more strongly to a crude one. Professor Rosewell has made the careful
conclusion that accessibility is associated with better employment and
TFL/REB/2065/1 14
population performance. She uses this analysis to present the implications
for the area surrounding the TGB of a change in accessibility. She also
concludes that the evidence suggests that a change in accessibility will
require additional policies. This argument appears to be ignored by Mr
Stern.
6.6 Mr Stern takes Professor Rosewell to task (5.6.15) for her comments
regarding other river crossings. The point she was seeking to make is not
that it is impossible to identify regeneration benefits from crossings
elsewhere - although there is some evidence of positive, if modest,
economic impacts from both the Humber and Severn crossings and of
strong population growth around the Tagus Bridge in Portugal (cited in the
Department for Transport’s Transport and City Competitiveness – Literature
Review). Rather it is that this inquiry is considering a proposal in London,
intended to assist with the regeneration of a particular part of the city, and
that nowhere else in the United Kingdom can completely replicate
conditions here.
6.7 Mr Stern in sections 5.7.1 to 5.7.4 draws attention to special characteristics
of the City of London. Since Professor Rosewell’s methodology has not
included the City, Mr Stern’s comments are not considered relevant. In
section 5.7.2 he asserts that the results from the analysis are ‘not exciting’
because the TGB ‘only’ generates an increase in employment of 8 per cent
for the TGB boroughs. It is not clear how he calculates this increase.
Using the data from the modelling exercise the increase in fact ranges
between 5.1 per cent and 7.9 per cent, depending on which scenario is
used. However, in the context of annual average growth of 2 per cent over
the last 8 years, and 1.4 per cent for the five boroughs of most interest, a
potential increase of this scale is considered by Professor Rosewell to be
highly significant.
TFL/REB/2065/1 15
6.8 Mr Stern asserts in 5.7.5 that correlation is the ‘obvious way of finding out if
employment density depends on access’. This is not true. Correlation is a
good screening device but neither it nor multiple regression techniques
provide an absolute test unless one can be sure that all the relevant
variables have been included in the analysis, and moreover that the
relationships are linear. An inspection of the Chart that Mr Stern
reproduces in 5.7.5 makes it clear both that there may well be a link, that it
is complex, and almost certainly non-linear. It is for these reasons that
Cluster analysis has been used. Cluster analysis enables us to capture all
the effects of missing variables and to abstract from them to identify the
impact of accessibility alone.
6.9 Mr Stern attacks the detailed analysis which looks at accessibility,
employment and population for all wards by asserting that it is useless
because it is technical and because no error bounds are presented (5.7.10).
6.10 The analysis is indeed technical. This is because it is a technical problem to
abstract from a range of measured and unmeasured reasons why
employment and population might exist in a particular local area in order to
focus on the variable of interest. The technical route chosen is explained in
both ordinary language and in equations in the Regeneration Statement
(D822). Further development of the approach and explanation in given in
TfL/76 in reaction to the Inspector’s queries. Mr Stern admits in 5.7.10 that
the analysis is not dishonest or discreditable but only that it does not
provide precise numbers.
6.11 Part of Table 8 is taken from Professor Rosewell’s proof (TfL/Proof/05/2)
as providing evidence of results which do not have any error bounds. In
fact Table 8 provides a range of results which cover both uncertainties
about modelling and about the range of infrastructure changes. It is
misleading to say that these forecasts ‘look very precise’ as Professor
Rosewell has been at pains to point out that precision should not be
TFL/REB/2065/1 16
expected. The impression of precision is given solely by this selective
quotation.
6.12 Mr Stern also includes in this table estimates of actual employment. He
does not give a source for these. The latest estimates for employment in
Greenwich and Newham are for 2003 and show 62,614 and 63,611. The
data available at the time the analysis was conducted for 2001 gave 57,989
for Greenwich and 65,597 for Newham. Since then there have been
revisions to the data and the latest estimates for 2001 give Greenwich at
61,495 and Newham at 70,653. On the basis of the most recent estimates
the increases that Mr Stern quotes should read 10.7 per cent and 10.0 per
cent.
6.13 Mr Stern conducts an alternative analysis in paragraphs 5.7.14 to 5.7.18.
He performs a simple linear regression between employment density and
the accessibility index and concludes that it is too poorly specified to draw
any conclusions from. From this in turn he concludes that it is impossible to
draw any conclusions from any other analysis either. This is not valid either
in statistics or logic. The simple analysis is indeed poorly specified. No
valid conclusion can be drawn from any statistics based on this analysis if
there are any missing variables likely to affect the result. The existence of
missing variables means that the coefficients will be biased and so is the
performance of the relationship. Since Mr Stern wishes to argue that
accessibility does not have any impact he must admit that some other
variables are relevant to employment. If they are not included in the
regression analysis he cannot conclude anything about the role of
accessibility one way or the other.
6.14 Second, it does not follow from the fact that a simple analysis does not work
that a more careful one which tries to address the issue of missing variables
therefore fails. While the desire to ‘size’ a potential relationship at the
TFL/REB/2065/1 17
outset is a sensible one, only the resultant more careful analysis can
support conclusions.
6.15 In paragraph 6, Mr Stern concludes that Professor Rosewell has shown that
growth may come with better access but also that decline may come. This
is not the result of the analytical analysis which shows that in London, better
access generally leads to better performance, though the extent of change
varies. He also draws the conclusion from a very limited data set that better
access goes with greater unemployment as a generality, whilst he attacks
Professor Rosewell for drawing conclusions from a much wider data set.
Finally he states that his is a common sense conclusion, that a slum will be
created by ‘putting the place people want to live and work next to or under a
motorway’. But he presents no evidence himself to support such a strong
contention.
6.16 Mr Stern argues in 5.6.14 that ‘In general, her whole approach of relating
access to employment, seems dubious’. As he suggests in his proof, It is
worth doing a reality check on this statement. If access had no role to play,
then it is hard to see why cities would exist. Cities impose costs on their
inhabitants, yet people are willing, and indeed increasingly willing, to inhabit
them. To state the obvious, cities bring people and activities together – in
other words gives them access. It seems fairly obvious that access has
something to do with why people live and work in cities. It then becomes an
empirical question to try and disentangle this effect from all the other
elements in the drivers of activity. This has been attempted here, with
reasonable robustness. It is not the whole story, which requires other
policies too.
6.17 Because this is an empirical question, other locations and places are not
relevant. We cannot compare the impact of accessibility on a major world
city with its impact in rural locations, or cities with different sets of activities.
TFL/REB/2065/1 18
There are many examples of where links have led to prosperity. Almost all
towns are built around such links.
7 Summary
7.1 Mr Stern says that Professor Rosewell’s figures show a negative link
between accessibility and employment. Nowhere does he show this. He
does use a correlation between unemployment and accessibility for five
boroughs but this is neither the same thing nor valid.
7.2 Mr Stern says that Professor Rosewell uses a complex argument to link
accessibility and employment. Professor Rosewell considers it simple and
straightforward to say that the ability to access an area will have something
to do with employment. Mr Stern then says Professor Rosewell relies on
rail data to prove this, which is not the case. The data used in the analysis
of the impact of the TGB covers all principal forms of access and not rail
data alone.
7.3 The City is excluded from the analysis of the impact of accessibility
changes from the TGB so it is not valid to say the theory has been built
around the City.
7.4 Mr Stern asserts that no reference is given for the conclusion that
employment density in London is associated with a strong economy, though
this is clearly referenced in paragraph 5.4 of Professor Rosewell’s proof as
The Case for London (D752). Moreover, this is not key to the argument
about a link between accessibility and employment potential. He says that
Professor Rosewell admits there is no link to population. Nothing could be
further from the case. Although it is the case that the population effect of
increasing accessibility tails off in comparison with employment (Professor
TFL/REB/2065/1 19
Rosewell (TfL/Proof/05/2) paragraph 5.5.7), the effect of TGB is large for
the particular changes which it creates.
7.5 Mr Stern misunderstands how modelling has been used. A partial model
which purported to capture accessibility effects while leaving variables
unmeasured would not be valid. Equally a model, as created here, which
employs a technique to wrap up all the effects other than accessibility
cannot guarantee that all the other effects will remain constant in the future
while only accessibility changes. It is for this reason that the calculation of
the impact of the TGB have been labelled ‘potential’ employment and
population changes. Changes in other aspects of the situation will also be
needed to realise potential.
7.6 No reference is given for Professor Rosewell stating that any level of
employment can be reached either with or without the TGB.
7.7 Mr Stern states that the proposition that accessibility is a necessary though
insufficient condition for employment is not proven. But he sets no standard
that he would be willing to accept that for proving such a proposition. He
then repeats that better accessibility is associated with lower employment
which Figure 1 in his 5.7.5 shows clearly not to be the case.
7.8 Mr Stern criticises the analysis of employment and accessibility for being
technical and complex. However, the central concepts of the modelling are
straightforward even if the application is technically complex - if the world is
complex, then so too must be the models which try to capture it.
7.9 Mr Stern presents a sizing calculation which is invalid as it relies on an
assumption that no other features are missing from the model.
7.10 In addition to the actual calculation being invalid, Mr Stern’s presentation is
also wrong. He says that his central view is that the TGB would create an
8% increase in employment ±13%. This means that the range in his view is
TFL/REB/2065/1 20
between an increase of 21% (8+13) and a fall of 5% (8-13). Taking his
example of Greenwich, where he says current employment is 85,000, this is
a range of between 102,850 and 80,750. The range of change is between
17,850 and a fall of 4,250. This is certainly not saying that a fall is as likely
as an increase. Further he presents a range of between 54,000 and
129,000 and it is not at all clear how Mr Stern is able to calculate such
figures.
7.11 It should be noted that employment in Greenwich is not anywhere near
85,000, and the latest Annual Business Inquiry gives a figure of 62,614 for
2003 (see paragraph 5.13 of this Rebuttal).
8 Conclusion
8.1 Mr Stern’s criticism of Professor Rosewell’s methods and conclusions boil
down to the fact that she has not claimed them to be something they are
not. If they were presented as forecasts, Mr Stern would doubtless be
critical of them for claiming too much. Critics of more conventional
approaches to identifying the economic development impacts of
infrastructure proposals have rightly pointed to the dangers of claiming
more precision than is possible in reality.
8.2 What Professor Rosewell’s analysis does do is to provide some theoretical
basis for the commonsense proposition that economic and social
development – in short, ensuring sustainable communities – is impossible
without accessibility. While Mr Stern argues this cannot be proven, he
equally does not bring forward any evidence (or “reality check”) to disprove
this proposition.
TFL/REB/2065/1 21
9 Annex 1
Extra Units Costs on Both Sides £840m
9.1 TfL do not accept that any of the additional construction or enhancements
referred to by Mr Stern is necessary.
9.2 In any event, Mr Stern’s figure of £20 million per kilometre for a single lane
is not accepted. The Limehouse Link was one of the most expensive roads
ever built and not a relevant source for costing.
Additional downside to living in Barking
9.3 The average number of households per km of road in inner London tells us
very little about the number of households that might live along widened
roads even if these were to be built. Further there is no evidence that each
household being in such circumstances would lose £10,000.
9.4 Even if roads were enhanced in the manner Mr Stern suggests, it is not
accepted there would be an automatic 16% increase in traffic.
Oxleas Wood
9.5 There is no basis for suggesting that the TGB would be extended via
Oxleas Wood to the A2. Reference should be made to TfL’s rebuttal to the
MTRU report on this subject (TFL/REB/4982/2).
Summary of Costs
9.6 Mr Stern’s figure of £1200m presumably includes Mr Ellison’s figure of £378
million referred to on page 2 of the document. This estimate includes the
cost of approach roads as well as the bridge itself and Mr Stern cannot
include this as any further part of “extra costs”.
TFL/REB/2065/1 22
Pollution
9.7 TfL does not accept any of the following:
• that there would be a 16% increase in traffic
• that a 16% increase in traffic would mean a 16% increase in pollution
• that any increase would apply to the entire population of the area within Mr
Stern’s two circles radius.
Non-Transport Spending
9.8 Alternative options have been assessed in the Annex to Tfl/REB/4982/1.
Since neither a heavy rail nor a DLR extension would meet the needs of
business to carry goods and services across the area.
9.9 So far as non-transport spending TfL agree with Mr Stern that other policies
and programmes are required to ensure that regeneration occurs in this
area.
Transport Spending
9.10 The London Plan (D620) contains proposals for 2 major street tram
systems, both of which are currently being progressed. The TGB serves an
entirely different purpose to these systems.
9.11 It is already intended to construct the GWT and the ELT and connect them
over the TGB using segregated public transport lanes. These will be
supplemented by other bus services. If at any stage there is sufficient
demand justification upgrade to the transit systems this will be considered.
TFL/REB/2065/1 23