How will Cambridge develop over the
next 50 years?
Cambridge Futures has attempted to
examine this question by projecting current trends into the future, and looking at how
different planning options would affect the Cambridge area.
Computer modelling was used to
simulate the effects of development in seven different planning scenarios. The planning
impacts of each of these scenarios has been evaluated in terms of economic efficiency,
social equity, and environmental quality.
make a consistent analysis of the alternatives for the future, two sets of assumptions
have been made concerning the number of people who might live in the area and the number
of jobs which might be available.
To facilitate analysis, employment has been divided
into basic or service employment. Basic employment is concerned with exporting goods and
services outside the region, and bringing money back into it which supports households and
services in the region. The rest is essentially service employment, the role of which is
to support the basic sector and the residential population.
Computer simulation models have
been used to estimate the likely outcome of the policies implemented for each option. One
of the models, MENTOR, simulates the workings of the market for location (land use) and
the other, SATURN, simulates the market for transport. The models estimate:
Location of firms and households. MENTOR calculates
the probability of firms and households locating in each area of the region, taking
account of the availability of commercial floorspace and dwellings, costs, accessibility
to transport, and the attractiveness of the area.
Price of commercial property and of dwellings. MENTOR
calculates the equilibrium price of the buildings. If the area is highly attractive, the
prices would increase, reducing the demand to locate there.
Transport flows. The model calculates the number of
people travelling between areas of the region for work, shopping, education and other
purposes. It also calculates the probability of using different means of transport, such
as walking, cycling, bus, train or car.
Congestion in the network. SATURN calculates the
number of vehicles using the road network during the peak hours, estimating traffic
delays, and thus the accessibility of different areas of the region.
From the results of the simulation models, it is
possible to compare the options under three headings:
Efficiency. Economic efficiency is
measured by calculating the cost of living and production costs for each area and for the
region as a whole. The cost of living includes housing, goods, services and transport.
Cost of production, measured by employee, includes floorspace rental, wage levels,
services and transport. Options which increase the regions costs would probably also
threaten its prosperity, making it less competitive.
Equity. Social equity is measured by
the composition of socio-economic groups within areas of the region. Highly segregated
location of, say, high income professional and managerial groups or of unskilled groups
would not contribute to equity. A more balanced socio-economic mix means affordable
housing and equitable opportunities for work and services.
Environment. Environmental quality
can only be established by more subjective criteria. Nevertheless some quantitative
estimates are possible, particularly traffic congestion, vehicle emissions and pollution
levels. The amount of open space in the form of private gardens and agricultural land, is
another indicator of quality. Impacts on man-made amenities such as buildings and public
spaces are more difficult to assess.
A consideration of all three aspects
efficiency, equity and environment should lead to a proper assessment of the
sustainability of each option. All three aspects are relevant and if one of them falls
short, the long term sustainability of the region will be impaired.