PLANNING FOR A SUSTAINABLE EUROPE? - TU Berlin

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Hence, the main economic argument in favor of ring roads, namely user time savings,
tends to disappear over time.
As for the medium- to long-term impacts of ring roads on travel patterns,
metropolitan structures, and – by extension – on the future competitiveness of the
agglomeration at hand, there is also no consensus in the literature. Crane (1999) provides
an excellent, exhaustive, albeit predominantly U.S.-centered overview of the rapidly
growing literature investigating causal links between urban form and travel, concluding
that “while research … is improving in several respects, our current understanding of
these relationships remains poor.” Crane’s main aim, however, was to assess the scope
for using land use as a determinant of affecting travel behavior, rather than the other way
around.
Four recent European studies explicitly investigate the effects of ring roads on
metropolitan development: Guitérrez and Gómez (1999) in Spain, Linneker and Spence
(1996) in Britain, and van Nes (2002) in Britain, Germany and Norway, and Falleth
(1999) in Norway. 14 Guitérrez and Gómez focus on measuring intra-metropolitan
accessibility, but most of their conclusions are rather tentative. Interestingly, the
investigated M40 ring road in Madrid was completed as recently as 1990-96 to relieve
congestion on an older, inner orbital motorway, the M30. The main rationale for the M40
was thus never to serve as a transit bypass, but always to accommodate increasing traffic
between the city center and suburban municipalities. In the end, Guitiérrez and Gómez
(1999:14) conclude that
14 In fact, Falleth’s study does not investigate ring roads but by-passes, i.e. partial ring-roads that are not
designed to encircle the entire town or city. The study remains highly relevant to our case study, however,
since this is of course what the M0 is in its current form.