alpbacher architekturgespräche 2003 - ATP

In most cities one is not charged for driving into the centre. However, examples such as Singapore and
London, who charge for the user of inner-city streets, show the dramatic effect that such road pricing
could have.Traffic in central London since the introduction of a five pound charge for entering the area
has fallen by 10%, increasing average traffic speeds and even making it possible to improve bus timetables.As
the income from this tax is directly used to cross subsidise public transport (underground improvements
and tram construction), a double headed process is working in favour of public transport.
Other examples also show that transport consumers are considerably more sensitive to price than
has previously been imagined.
• The operators of the M1 motorway in Hungary have gone into liquidation due to the unexpectedly
low toll income
• The private financing of the Warnow by-pass in Rostock only succeeded due to massive state
subsidy
• Other examples of private financing such as the Strelasund Bridge or the Hochmosel bridge on the
B50 have been put on ice because the tenders have not received enough private interest.
In all the above examples, traffic-use predictions were very high, leading to very positive estimates of
economic return. However, the reality is that the values used in cost-benefit analyses of transport projects
are generally exaggerated (“appraisal bias”). As three-quarters of these benefits are calculated on the
basis of time and cost savings that the private user can expect, it follows that for projects where heavy
tolls are to be applied the estimates of return have consistently exceeded reality. Flyvberg, Bruzelius und
Rothengatter (2003) have shown in their book “Megaprojects and Risk” that transport projects should
be based on a substantial part of private financing, in order to avoid this “appraisal bias”. Put otherwise
– the valuation of transport infrastructure by means of public standards generally results in overoptimistic
use predictions and, consequently, overprovision. But this overprovision tends to remain unrecognised
as there are no tolls to demonstrate whether demand was as predicted.
Urban Structure and Mobility
Urban structures have in the past developed by means of cause-and-effect, favouring a stronger spatial
dispersion of residential areas and encouraging private traffic.
Urban planning can attempt to bring order to this cause-and-effect induced chaos. But it is questionable
which urban structure could contribute to the diminution of individual private traffic. Newton
(1999) for example compared the following development options for Melbourne:
• Business-as-usual city – further development according to current trends
• Compact city – increased residential density in the centre
• Edge city – increased residential and employment density at certain hubs and parallel investment
in the transport infrastructure at these hubs
• Corridor city – radial axial development from the main centre to subsidiary centre and integration
with attractive public transport
• Fringe city – development of the outer suburbs
• Ultra city – development much further out of new regional centres, connected by high-speed trains,
in order to release pressure on the centre
The basic organisations of these alternatives are set out in diagram 3.According to Newton, the corridor
city offered the best option in terms of travel distances, energy-use and the environmental
concerns of the population. Steierwald, Heimerl, Kaule und Rothengatter (1995) also came to the
same conclusion with regards to the optimal environmental effects when comparing compact with
axially concentrated cities. However – one should not overemphasise the significance of these results
by forgetting that cities come about as the result of a complex historical organic process and cannot
be simply developed by means of abstract recipes. In all cases it is a series of individual measures that
can perhaps combine to a positive result (Waßmuth, 2001):
• Mix and optimal density of uses,
• Car-reducing residential forms,
• Universal parking charges - including on the periphery,
• Traffic calming and car-free residential areas,
• Low traffic urban areas,
• A full offer of alternative transport options (public transport, car sharing, non-motorised transport),
When one examines the extent to which such measures really lead to settlement structures with
lower private car use, the results are mixed 2 . In the centres of German cities, development policies
have been so successful that traffic really has been reined in and this has largely been achieved through
such preventive measures as pedestrian precincts, speed limits in residential areas, parking restrictions
and parking charges.
Furthermore in some cities (such as Berlin) the block structure of residential districts has been widely
retained and this form has shown great advantages over either ribbon developments of single-family
houses or high rise apartment blocks.The traditional six storey block offers the possibility of building shops
at ground level with apartments above. Pedestrian distances are reduced and public transport easier to
reach. And - thanks to the different design of block facades and the commercial use of ground floors -
much more varied forms can be achieved than by single-family houses or high rise apartment blocks.
The biggest problem in planning the low-traffic city is on the periphery and at secondary hubs.The
problem is less one of appropriate legislation 3 and much more the fact that these areas are become
ever more dispersed.The reasons for this are primarily economic and long-term collective interests
are not considered.The key is the supply of land - and this is principally driven by the following factors:
• The price of land - which falls steadily from the centre and hence incentivises the drift to ever more
distant locations
• The quality of life, which is perceived as much higher in a green environment where the ecology is
in better shape and one (and one’s children) feels more secure,
• Lower commuting times and costs due to the construction of tangential highways and the almost
universal availability of private cars, which have made the distance to public transport almost irrelevant.
On the supply side the following market mechanisms are also significant:
• An increase in the tax income of districts which provide such land
• The possibility of sharing the spoils of economic development
• Competition between districts for tax income and new industrial development and the potential
reward for politicians who are successful in attracting development,
• Local pressure on the decision-makers by means of economic pressure groups,
One conclusion is that planning laws have been by-passed in many ways in order to push through developments,
be they individual, collective or outright counter-productive.This phenomenon has in the post-war
years led to the above mentioned cause-and-effect spiral promoting both higher land use and higher car
ownership, which has in turn led to even more dispersed settlements and a further sidelining of public
transport.The income from such economic measures as in Singapore and London would be a means of
arresting this cause and effect spiral and steering incentives in another direction.At the same time there
has perhaps not been the political will to wield price politics as a means of controlling traffic on the edge
of cities and improving the relationship between city and country. It is more common to wait for traffic
problems to emerge and then to try and solve them by physical measures (tunnels, bridges and ring-roads),
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