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What Transport for Cambridge?
EXECUTIVE SUMMARY
Introduction
Cambridge Futures is an independent not-for-profit organisation funded by voluntary donations from local
organisations and individuals. It has an Executive Committee and employs a researcher from the University
of Cambridge.
Cambridge futures was founded in 1997 as a joint initiative between the City and University to inform the
debate about the future development of Cambridge. The first study tested several development options and
found that developing along improved transport links, increasing the density of development within the city,
extending the urban area into the green belt, and providing free easily accessible internet communications
were the four best options when assessed across a range of social, economic and environmental criteria. A
public consultation encountered less opposition than expected to expansion into the green belt and found that
people recognised the need for growth. The findings have greatly influenced the recently revised Structure
Plan.
However, the first Cambridge Futures study found that the large amount of proposed new development for
the Sub region would cause severe traffic congestion, regardless of where the development is located. This
prompted a second Cambridge Futures study, launched in 2001, called ‘What Transport for Cambridge?’
Background
The recently revised Cambridgeshire and Peterborough Structure Plan is a reversal of over 50 years of
planning policy. The tight green belt constraints around Cambridge are being relaxed, and there are
proposals for major developments around the edge of the city, that will increase the size of the urban area by
around 40% by 2016. The target rate of house building across the Sub region is to be increased to 2,800
homes per year, (an increase of 40% on current levels). Clearly this level of growth will result in a
corresponding increase in travel, putting an even greater strain on a transport infrastructure that is already at
capacity in many areas and suffering from a deficit of investment.
This study is not about designing a particular transport solution for Cambridge. Its main aim is to broadly
demonstrate the limits of what could be achieved by different types of transport measures, both individually
and as a combination.
Method of carrying out the transport study
The options were tested using the land use transport computer model of Cambridgeshire County Council.
This contains large amounts of detailed information about the population, homes, jobs, and shops in the Sub
region and the roads and public transport systems. A version of this has been developed, called the 2016
Reference Case, which includes forecasts the population and jobs for 2016 and contains the new housing,
employment floor-space and retail space proposed in the Structure Plan up to 2016. This consists of 47,500
new dwellings from 1999 to 2016 (equivalent to building another Cambridge) and those transport schemes to
which the government had already committed its support.
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Significant transport schemes in the
Structure Plan include, A14 widening
and
highway
improvements,
Huntingdon to Trumpington rapid
transit scheme, a new rail station at
Chesterton, improvements to M11
junction 13, a new A14 interchange
near Fen Ditton with a road link to
Airport Way, and a road link from
M11 Junction 11 to Addenbrookes
Hospital. (The Structure Plan proposes
a rapid transit link between east
Cambridge and the city centre but the
route and level of service in unclear, so
it has not been included in the
Reference Case.)
Figure 1: Transport proposals in the Structure Plan, (only the
committed schemes were included in the Reference Case)
Note: The options were tested
before the government announced
its recent proposals for a major
increase in house building.
Cambridge is part of one of the
‘Sustainable Community’ areas
targeted for development which
includes the M11 corridor and
extends to Peterborough. Future
house building targets are now
likely to be higher than in the
Structure Plan, creating an even
greater
need
for
transport
improvements.
Figure 2: Structure Plan development areas around the City
The land use transport model represents the supply and demand for dwellings, floor-space and transport. It
predicts how property values will change in the future, depending on travel conditions. If traffic congestion
gets worse in an area, fewer people will want to live and work there, resulting in lower ‘rental’ values.
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Conversely, if an area become more accessible, then the population, jobs and ‘rents’ tend to increase. This
sophisticated model can estimate how the transport options would affect different types of people. It can
predict how the options would affect the cost of living of households and the cost of production for different
industrial sectors, based on an aggregation of travel time and costs, property rental values, and the cost of
services. The model also predicts travel by different modes, and their environmental impacts. The computer
model provides a framework within which to test and compare the options in a consistent way to show their
relative merits and shortcomings.
Cambridge Futures carried out an independent audit of the model and made the transport part more detailed
so that it became suitable for testing the options. Cambridge Futures specified the inputs to the model and
analysed the outputs. Hence, although Cambridgeshire County Council generously provided full access to
the model and the resources to run it, the Cambridge Futures results are completely independent of the
Council.
Options
The transport study took the 2016 Reference Case as the benchmark against which to compare four distinct
transport options. Each option represents transport measures in addition to those proposed in the Reference
Case. Each option summarised below represents an extreme example of a particular transport policy:
Cycling and walking – a major expansion of the cycling network including and outer circular route, and
better connections from Cambridge to surrounding villages. Unfortunately, the model did not represent the
cycling and walking network in enough detail to allow new routes to be tested. Also, some of the proposals
would make cycling and walking more attractive without significantly reducing travel times, and these
qualitative improvements are currently difficult to represent in a transport model. It would have required
resources beyond the scope of this study to adequately build this capability into the model. However, the
study did show how other options would affect cycling and walking. For example, road pricing would
encourage people to cycle or walk rather than travel by car.
Public transport – rapid transit
routes segregated from traffic to
avoid delays and with tunnels
under the city centre, to the rail
station and east Cambridge.
Figure 3: Public transport option
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Figure 4: Public transport option –Entrance to the tunnel under the City centre
Highways – an orbital road around Cambridge with link roads running parallel to the A14 and M11 to cater
for local traffic, and tunnels under Shelford and the hills south of the city to reduce its environmental impact.
The Structure Plan already contains identifies the need for new road links south of Cambridge from the M11
to Addenbrookes, and north east of Cambridge from a new A14 interchange near Fen Ditton to Airport Way.
Also, there is a government
commitment to widen the A14 west
of Fen Ditton and the London South
Midlands multi-modal study has
recommended the widening of the
M11. All of these schemes could be
integrated within an orbital highway
with parallel link roads on the A14
and M11. However, this needs to be
considered urgently before schemes
are built which could preclude or
duplicate an orbital highway with
parallel link roads.
Figure 5: Orbital highway option
Figure 6: Orbital around the East and South of the City
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Road pricing – to manage the
demand for road space by imposing
a charge on drivers during the busy
morning and evening periods
equivalent to £3.50 per day for
crossing an outer cordon and
£0.50p per day for driving within
the cordon. Drivers would have
free access to the park and ride sites
and no charge off peak 10am to
4pm and 7pm to 7 am.
Figure 7: Road pricing option
The road pricing option tested a
system
based
on
similar
technology to the London
congestion charge scheme. This
uses number plate recognition
cameras to detect vehicles as they
cross an outer cordon. There are
also roving detector vehicles
within the cordon area. For
Cambridge, the cordon was
assumed to encompass the whole
of the urban area.
Figure 8: Entrance to road pricing cordon
Combined option - the study also tested all of the above options together in combination.
This study has not tested ‘soft’ transport measures, such as ‘green’ travel plans, or the possible effects of new
technology. Currently, there is not enough evidence to predict the long term effects of these sorts of
measures on travel patterns.
The Findings
The Reference Case: The committed transport schemes in the Structure Plan will not be sufficient to cater
for the large increase in travel and many areas of the city will be gridlocked. The delays would jeopardise
economic growth, worsening environmental conditions and the quality of life.
Comparing conditions across the Sub region in 2016 with those in 2001, there would be increases of around
40% in the cost of living, 30% in production costs for employers. In Cambridge the increase in cost of living
and cost of production would be even higher, at around 70% and 60% respectively. (Note that the economic
indicators exclude inflation). There would be an increase of 30% in fuel consumption in and around the
Cambridge urban area which corresponds to a 30% increase in transport related carbon dioxide emissions.
(The amount of carbon dioxide released is used as a measure of greenhouse gases contributing to global
warming.) The fuel consumption forecasts do not take into account future improvements in fuel efficiency.
However, any fuel efficiency improvements are unlikely to compensate for the increase in car travel.
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Table 1 summarises these findings using the cost of living in Cambridge as a measure of social equity and
production costs for the sub region as measures of local economic conditions. Carbon dioxide emissions
have only been calculated for the Cambridge urban area and its immediate surroundings, and not for the Sub
region as a whole. The cost of living is an important indicator of social equity. If the cost of living increases
significantly, this is generally the greatest hardship for the disadvantaged in society who would find it more
difficult to afford to live in Cambridge. The higher production costs show that the Sub region would become
less competitive as an exporter.
Table 1: Forecast increases by 2016* unless there are additional transport measures
Scenario
Key Indicators
Social
Economic
Environmental
Cost of living
Production costs
Carbon dioxide from traffic
(Cambridge)
(Sub region)
(Cambridge)
Reference case
+ 70%
+ 30%
+ 30%
* Note: Compared to 2001 Base case
As explained earlier, cycling and walking improvements could not be explicitly tested. It is assumed that
developments proposed in the Structure Plan will be designed to facilitate cycling and walking. It is
important that cycling and walking provision continues to improve as Cambridge expands and average travel
distances increase to try and maintain the high levels of cycling and walking. Otherwise traffic conditions
are likely to be worse than forecast.
Table 2 compares the following options on three of the key indicators.
Public Transport: A fast and extensive local rapid transit system would not result in a significant
improvement in traffic conditions. Tunnels would provide an opportunity for improving the conditions for
pedestrians in bus and rail stations and the St Andrews Street area and the level of service for public
transport users. However, these benefits do not justify the high construction costs of tunnels.
Highway improvements: The orbital road would cater for the demand for traffic movements and provide a
link between the major proposed developments around the south and east of Cambridge, such as the
proposed Addenbrookes medi-park, Southern Fringe housing and Airport site. This would be particularly
advantageous around the south and east of Cambridge where there is currently a lack of capacity for orbital
traffic movements. The road would probably pass the governments economic value-for-money tests, even
with the expensive tunnels around the south of Cambridge. It would help to contain the increases in the cost
of living and production, by improving accessibility. It would improve overall traffic conditions in
Cambridge and for the Sub-region as a whole, but there would be a slight increase in the number of car trips
and distance travelled which results in a forecast increase in carbon emissions compared to the Reference
Case.
Road Pricing: This option would raise a lot of revenue, (around £40 million in the first year of operation,
declining to around £30 million per year over the first 5 years as households and jobs relocate to avoid
paying the congestion charge. The charges substantially increase the cost of living and production costs.
Under current government legislation local authorities can re-invest this revenue locally in transport for the
first 10 years of operation. However, after 10 years the Treasury can choose to keep the revenue. For the
purpose of testing this option in isolation, the findings do not take into account the benefits that could results
from re-investing the revenue. This option would results in a gradual segregation between those who live
and work within the road pricing cordon and those who live and work outside the cordon, as firms and
households relocate to avoid paying the charge. This option would adversely affect social equity because
property prices within the cordon would increase, so that fewer lower income households could afford to live
in the city. However, it would greatly reduce traffic levels in Cambridge and overall carbon emissions. A
more optimal version of this option could have been developed if more resources had been available. For
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example, by testing different charging regimes, by charging over a much wider area, and, or reducing vehicle
taxation to compensate for the increases in travel costs.
The option tested could raise in financial markets over £120 million of capital based on future revenues
streams from the charge, depending on whether the agency responsible was public or private, and the length
of time that revenue can be collected by the agency (hypothecation period), and whether there is an off-peak
charge.
Combined Option: The options work well together as a whole. Road pricing acts as an effective means of
managing the demand for car travel in Cambridge and the rapid transit system gives people a fast and
reliable alternative to the car. The orbital highway allows drivers to more easily access the park and ride
service that best serves their destination without having to pay the congestion charge. This option would
greatly improve traffic conditions in Cambridge. The overall cost of the combined option is high, mainly
due to the cost of the public transport tunnels. The revenues from the road pricing would partly fund the
scheme. Various combinations of the options ought to be tested by further studies. For example, it may be
possible to achieve similar benefits at a lower cost if the road pricing reduces traffic levels in the city centre
to a level where a segregated rapid transit system could be implemented at ground level.
The most surprising finding is the substantial reduction the cost of living in the Sub region, (Figure 9). It is
also likely that beyond 2016 this would have a knock on effect on production costs for local industry making
the Sub region more competitive. The combined option would help the local economy by reducing delays
due to traffic congestion, reducing the cost of services, and increasing accessibility between home and jobs
thereby effectively expanding the easily commutable catchment area of the city and reducing average land
prices.
Road pricing
Reference case
Public transport
Orbital highway
Combined option
Table 2: Differences between the options and the Reference Case
Options
Key Indicators
Social
Economic
Cost of living
Production costs
(Cambridge)
(Sub region)
Environmental
Carbon dioxide from traffic
(Cambridge)
Rapid Transit system
- 8%
√√√
- 3%
√√√
0%
-
Orbital highway
- 17%
√√√√
- 5%
√√√
+16%
xxxx
Road pricing
+ 9%
xxx
+ 5%
xxx
-8%
√√√
Combined option
- 20%
√√√√√
- 4%
√√√
0%
-
Key:
√ better than the Reference Case
x worse than the Reference Case
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The findings were presented to the public in the autumn of 2003 at an exhibition and they had extensive local
media coverage in the Cambridge Evening News. The responses to a questionnaire have been analysed by
Cambridge Architectural Research and the results of the public consultation will be announced at a seminar
in July-04.
Conclusions

The committed schemes in the Structure Plan, (i.e., the A14 improvements, Huntingdon to
Trumpington guided bus, and M11 to Addenbrookes link road) will not be sufficient to cater for
the large increase in travel resulting from the rapid growth envisaged for the Sub region. Unless
there are additional transport measures, there will be severe traffic congestion with adverse
consequences for the environment and local economy. This threatens the forecast levels of
growth in employment and the viability of the proposed developments.

The study shows that increasing highway capacity is the only individual measure that would
significantly benefit the local economy and cost of living. However, there would be more car
travel unless accompanied by effective demand management.

Improving public transport in isolation has little effect on reducing congestion or helping the
economy. It would be necessary to improve public transport before introducing demand
management measures, such as road pricing, so that people have an acceptable alternative to
using their cars.

Simply restraining the demand for car travel without investing in greater transport capacity
would have a damaging effect on the local economy and, if done by pricing, would adversely
affect those less able to pay.

The study shows the importance of transport to the success of the Sub region and that a
combination of transport measures could help achieve the forecast levels of growth in a
sustainable way.
This Cambridge Futures study demonstrates the importance of an efficient transport system to maintain the
competitiveness of the Sub region. Further study is required to assess the most appropriate combination of
transport measures. It is important that proposed developments are planned so that they do not preclude the
implementation of appropriate transport schemes.
It is hoped that this Cambridge Futures study has helped to stimulate the debate about transport policy for
Cambridge and broadly demonstrate what could be achieved.
References
Cambridgeshire and Peterborough Joint Structure Plan Review, Deposit Draft, 2002
Echenique, M.H. & Hargreaves, A.J. (2003) ‘Cambridge Futures 2: What Transport for Cambridge?’
Cambridge Futures/University of Cambridge.
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