facilities which have been provided as terminals (in the UK at Ashford, Waterloo, and
in the future at Ebbsfleet, Stratford and St Pancras) and railway track (CTRL) which
would not have been developed without the Tunnel itself plus those parts of the
French LGV high speed rail network and those parts of the road systems which have
been developed to cater for through UK-continent traffic. We also need to distinguish
between the project as the provision of fixed infrastructure and the project as the
development of new services using that infrastructure.
The second set of issues concerns the nature of the impacts. This study seeks to
combine two conventional approaches: investment impact studies and transport
impact studies. In the first of these it is usual to distinguish the direct effects of a
project (the project’s own generation of employment and household incomes) from
the indirect effects (in enterprises supplying the project with goods and services) and
from induced effects (the economic multipliers in employment and incomes arising
from the spending of incomes arising from direct and indirect effects). Transport
impact studies conventionally focus on the two traffic effects of a new facility:
diversion of traffic to a new facility and thus away from any pre-existing facilities,
and generation of traffic as productive activities and households respond to changes
in generalised costs occasioned by the new facility.
In studying the impact of the Channel Tunnel these various effects are seen to be
inter-related. Traffic diversion may itself have direct (negative effects) as the loss if
traffic to the new facility results in reduced revenues, employment and incomes in the
existing facilities. These effects will be even more acute if the competition from the
new facilities results in classic competitive behaviour (price cutting and reduction in
labour costs) by operators through the pre-existing facilities. Similarly it is evident
that traffic generation may also include the new establishment or inward re-location
of productive activities or households responding to the changes in generalised costs.
This discussion introduces the temporal and spatial dimensions of impacts. In the
temporal dimension some effects become evident at an early stage in the project (for
example the employment arising from initial construction and early phases of
operation) but others may be delayed for some years or even decades. In addition
there is a distinction between impacts which are short lived (construction
employment) and those which are quasi-permanent (employment in operation). In the
spatial dimension a similar distinction must be made between those effects which are
localised (usually close to the new facility or associated developments) and those
which are felt at a regional or national scale
The last feature of the model which needs to be identified is that many of the
statistical series which might be expected to show evidence of impacts reflect more
than one of the processes identified and may indeed reflect changes in macro-
economic conditions which would have occurred without the project. So, for example,
any changes in the aggregate flows of road freight vehicles on the tunnel shuttles will
include traffic diverted from a variety of alternative routes and modes, traffic
generated by short run responses to changes in costs, longer term traffic generation
and changes in volumes due to the increased volumes of international trade between
the UK and the Republic of Ireland on one hand and the rest of Europe. Similarly
changes in employment in the immediate locality of the tunnel terminals will include
changes due to direct effects, indirect effects, traffic diversion and traffic generation