Transport and economic development - Transport Policy and Planning in Great Britain - page 15

worthwhile (in effect that the overall cost of the journey is greater than the value
of the activity forgone).
Strangely, given the enormous amount of public expenditure on transport over the
last 50 years, there is no official process which has monitored what overall improvement
has been derived in savings in travel time and/or distance. (Individual schemes may
demonstrate improvement to gain initial approval, but their value over the longer term
is influenced by action or inaction on other parts of the network and how the pattern
of travel demand evolves.)
On the nation's road network there have clearly been very large time savings along
the main inter-urban corridors where motorways and other dual carriageways have been
built. Many 'A' roads forming part of the primary route network connecting principal
towns (those marked by green-backed road signs) have also had their alignments
improved permitting higher speeds and greater opportunities for overtaking. Journeys
not directly served by these routes have not experienced any absolute disadvantage
(because the traditional routes remain and may even have benefited from some
displacement of traffic). But equally it is not clear, taking into account the additional
expense involved in making 'detours' to use the improved routes, what proportion
of these other journeys have benefited and by how much. Even without the effect of
consequential changes in land use, areas of the country away from the main corridors
will have experienced relative disadvantage in seeing little improvement in travel times
from highway investment for journeys, say, of less than 25 miles.
For rail passenger journeys a similar pattern of change has taken place through
improvements in track, signalling and motive power but with the added dimension
of higher frequencies (as well as higher speeds) on the trunk routes. Hence journeys
which are no longer catered for by through services incur the penalty of one or more
interchanges as well as possibly a more indirect route. These disbenefits may or may
not be offset by the gains of greater speed on the trunk route - the length of trip
is likely to be a determining factor. However the change in conditions across the
country is more polarised than with road travel because whilst trunk services have
been improved greatly many smaller towns have lost their rail services altogether. For
people without a car living in such places (or in rural areas more generally) merely
gaining access to the network can be problematic as there is no coherent system of
connecting bus or coach services. At the other extreme however the development of
high speed trains has given special advantage to cities which can command limited
stop services. In travelling by car from London to Newcastle for example there is no
gain in average speed to be had from driving all the way along the A1 than to any of
the towns in between. That is not the case with rail travel.
As well as noting the changes in travel times on the national road and rail networks
separately we can also observe changes in their relative position. Historically railways
were built to serve the centres of towns. Motorways and trunk roads by contrast
have mostly only been built to provide connections at or near the edge of towns as
they evolved some 120 or more years later. The standard of main roads connecting
the centres of towns to their periphery are very variable and are often affected by
congestion. Hence in considering the relative speed of inter-urban travel measured
'door to door' it is critical whether the origin and destination of trips is close to the
centres of towns or to their outer edge. (The same consideration applies in comparing
rail and air services between the principal cities over about 150 miles.) Over the last
half century the significance of this has grown enormously with the decentralisation of
much business and retail activity (attracted by the vastly improved opportunities for