Wednesday, February 15, 2012

The impacts of major transportation infrastructure on the form and function of the urban space: the case of the "Athens urban freeway"

by Maria Zifou and Constantinos Serraos

In the summer of 2004, the newly constructed Athens urban freeway was put into full operation. The freeway is the first concession roadway project (Public-Private Partnership, PPP), and the first urban toll road in the country and is considered one of the major urban highways to be constructed at the European level not only because of its size and scale, 65,2 km long, but also because of the fact that a large section of the freeway is bisecting the dense urban fabric of a city such as Athens which has a population of over 4 million people and 5000 years of history. The new freeway was built with the purpose to bypass the city center and the expectation to relieve the overly congested roadway network of the city of Athens that was suffocating by everyday traffic gridlocks and high air pollution levels thus, achieving substantial traffic, environmental and economic gains.
The construction of new highways has always been a prominent, though much debated, transportation policy response to address the continuously increasing traffic congestion problems that point to the automobile dependence of the contemporary city. The construction of new highways, which in the 1950’s and 1960’s mainly took the form of peripheral and radial routes, was mainly justified on the basis of their implied ability to reduce travel times, to save fuel and to reduce emissions mainly due to improved travel speeds. Moreover, assumed savings in travel time were translated into economic gains which were calculated at different rates in accordance with the assumed value of travel time in each particular city that was under study.
However, the policy of evaluating transportation projects only on the basis of their effectiveness to improve mobility has substantially changed reflecting changes in the transportation planning approach as well as the prevalence of the environmental agenda. The first major factor impacting the way transportation systems are evaluated relates to the adoption of a different definition for the urban transportation problem that is being redefined from a problem of congestion to an accessibility problem (Banister, 1994). In this new context, the goal is not the ease of traffic movement but the improvement of accessibility to people and facilities, putting an emphasis on the equitable distribution of access and the minimization of discrepancies in personal mobility. The prevalence of the sustainability agenda is the second factor that has influenced not only the nature of the transportation policy but also the evaluation of individual transportation projects by pointing out the external effects of transportation systems and projects on both environmental functions as well as on the structural organization of urban areas. Thus, at one level, the environmental agenda has forced transportation systems to meet sustainability criteria which means that transport planning must minimize the external effects of transport by not only acknowledging “the long term streering role of spatial structure and dynamics” but also by integrating issues related to the environment, safety and security and public health (Himanen, Lee-Gesselin & Perrels, 2005). At a second level, by focusing on the important interrelationship that exists between travel patterns and urban form it emphasizes the enormous impact transportation policies and choices of transport mode have on urban structure. More specifically, increasing evidence – drawn from research on sustainable cities - has shown , among others, that automobile dependence promotes road expansion and sprawling growth patterns both of which spur new travel (Williams, Burton & Jenks, 2000; Newman & Kenworthy, 1999), that there is a critical
density point, of about 20 to 30 persons per hectare, "below which automobile-dependent land use patterns appear to be an inherent characteristic of the city" (Newman & Kenworthy, 1999: p.100) or that there is a statistically significant positive relationship between the amount of urbanized land area and energy consumption. The purpose of this paper is to make an assessment of the impacts of the new Athens freeway on urban form, the urban environment as well as on travel demand. Because of the short operating period of the project and the lack of relevant raw data, only a qualitative assessment will take place at this point regarding the short range effects of the freeway, that is the direct construction impacts and first year operating conditions.

more about the similar subjects:

European Urban Sprawl: Sustainability, Cultures of (Anti)Urbanism and »Hybrid Citysc apes «

Understanding the Impact of Transportation on Economic Development


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