INFRASTRUCTURES AND TOWN PLANNING POLICIES Orientations
and innovative experiences of the new culture of sustainability
text and translation by Giuseppe Di Giampietro, arch.phd (2). Published in URBANISTICA n.o 115, the magazine of the Italian National Urbanism Institute: special issue dedicated to Transport, to be released in the winter-spring 2001
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review of the Italian and international literature of the last twenty years
we can read the evolution of the relationship between transport infrastructures
and the urban environment. In the past years a lot of researchers deeply
investigated the relationship between new infrastructures and regional
and urban dynamics, particularly analysing the effects of transport investments
(Di Giampietro/CRT 1989;
editor 1995). Comparing such studies with the present orientations
of the research and the practice of planning in the most advanced countries,
a clear change of orientation on such themes can be noticed.
Paradoxically, it almost seems that the view has changed "from the paradigm of the effects of transport on the land use, to the inverse one of the influence of land use policies on the mobility system and commuting, and therefore on transport infrastructures". Actually, in the most innovative experiences in Europe and America, almost everywhere this change of point of view has accompanied the rise and consolidation of the new paradigms of sustainability and the idea of integration between transport and land use policies, of traffic reduction and traffic calming. Some countries are experimenting policies of the reduction of parking standards, or town planning policies oriented to the integration of functions and land uses able to reduce the mobility demand and the dependence on the car. In several countries attention is paid on the impact evaluation of works and actions on the traffic and the mobility, and the practice of Transport Assessment is rising (France L. 95-101, UK Road Traffic Reduction Act 1997, USA The Ahwahnee Principles 1994).
In the second part of the article the importance of regulations and standards for the development of innovation and quality in the design of roads is analysed, giving the results of a national research (3).
the land use - transport relationship
|.||.||.The new paradigms of the relationship between transport and land uses|
arch, phd, contract researcher at the DST-Politecnico di Milano is responsible for the annual continuing education courses The Design of Roads and Roundabouts, inside the Permanent Education Program of the Politecnico di Milano (http://formperm.elet.polimi.it/)
He is also administrator of the documentation centre Webstrade Archives and of the homonym e-magazine with the relative Internet sites
(3) Among the final products of the MURST research are some operative tools, defined inside the same search, that can contribute to update the culture of design of roads towards a sustainable mobility approach: the Road Design Regulations Archive on CD ROM (Archivio Normative Strade), the Standard Road Design Guidelines (Regolamento Viario tipo) and the electronic tools for their dissemination (The Internet site http://www.webstrade.it/, with the relative electronic magazine released to a mailing list of more than 2.000 Italian readers). All these tools help the knowledge of the best Italians and foreigners norms, experiences, handbooks, and meaningful case studies; they also help their dissemination outside the university. An useful tools, studied particularly to give operative power at local level is the Standard Road Design Guidelines, which is a regulation tools imposed by an Italian national Act to which the law attributes a role of control in the design and management of the road space and that can become strategic for urban and transport planning (Corda-Di Giampietro, 2000)
|.||In the United
Kingdom the evaluation of impact and the control of coherences and compatibility
between transport investments and land use policies are requested in the
proposals appraisal of a new infrastructure (Guidance on the New Approach
to Appraisal of Road Investments Proposals, DETR
1998). But an evaluation of the impacts along with an integrated planning
are also requested in the proposals of big building complexes, for which
the evaluation should analyse the consequences the construction will have
on the system of the mobility (the Transport Impact Assessments, in the
The same attention, although with a different approach, is paid in France compiling the “Plan d'Occupation du Sol” of the zones along the expressways and arterial roads, according to the 1995 Protection of roads Act (France, L.95-101).
Besides, in the planning of new development proposals a multifunctional choice of uses is often recommended in order to reduce the mobility demand, assuring accessibility with modal alternatives to the car, and to improve the social integration of the new complexes (Guidelines for the Design of the Interchanges, DETR 1994, Places Streets and Movement: a Companion Guide to Design, DETR w.d.).
Therefore, the project of new big buildings will have to deal in a sustainable manner with the mobility and transports systems and diminish the car dependence.
planning in Italy
|.||The hope to push forward the local development and the expectations of economic regional growth, which were attributed to the realization of new infrastructures in the past, are less and less central in the evaluation of big transport infrastructures proposals. Requests for a traffic reduction are made more precise and definite to limit the development of new infrastructures, and also in the case these are planned to be built, however they have to respect the criteria of compatibility, sustainability and integration with the other land use policies.|
|the 1997 road traffic reduction act in the UK||.||In the United Kingdom the Road
Traffic Reduction Act 1997 ordered the local authorities to prepare
a plan for traffic reduction, with the listing of objectives, strategies,
criteria, measures and planning policies to reach such objectives. Reducing
the construction of new roads and a better use of the existing ones are
among the stated priorities.
A recent paper of the English Government (DETR, Planning Policy Guidance 13: Transport, 1999) takes up position for integration between transport policies and land use planning, above all in local planning, with these primary objectives:
|policies for traffic reduction||.||Among the
principal strategies of local land use planning, which are indicated by
the English paper, there are:
|maximum allowed parking standards||.||For instance, among the land use
regulations that influence the transport system, recommendations to national
level have brought the revision of parking standards for new developments
in the United Kingdom, moving them from the notion of minimum requested
to that one of maximum allowed. The adopted standards are finalized to
the reduction of the dependence on the car and to promote sustainable transport
choices in the big building proposals, with a realistic sizing, tested
and to a large extent already in use at local level, to which the economic
activities and the consumers can adapt without traumas (Tab. 1, from DETR-UK
Along with the new parking standards the thresholds are fixed beyond which the redaction of impact studies of the proposal over the transport system begin compulsory (Transport Impact Assessments).
transports and land use policies
the Barnier Dupont highway Act in France
From the urban planning point of view, the most meaningful experiences, as the French law 95-101 (named "Barnier-Dupont Act"), have set the attention of planners to the risk that the big transport infrastructures become environmental detractors for the crossed zones; but they have also shown the potentiality of the infrastructures as planning occasions for the qualification of the same zones and to strengthen the settlement system. The recent French suburban roads protection Act (regarding those roads not yet jeopardized by the curtain building), has imposed a no building zone limit over the suburban section of all arterial roads and expressways, along a band 150 to the 200 meters wide from the centre of the road axle, unless, at local level, an executive land use plan is adopted for the development of the same band interested by the infrastructure. The plan is requested to be able to justify the need of transformation for that area, and to analyse the effects of the intervention on the area crossed by road. For the French law the themes to take in consideration are, those of the evaluation of the harmful effects of the road, the safety, the architectural quality, the urban quality, the landscape in the area alongside the road (CERTU 1997 and CERTU 1998). The law has already entered the French Code of urbanism.
Linked to the duties the law has imposed alongside the road protection bands, an interesting reflection on the strategic role of the "boulevards urbains" in shaping the urban form has been developed in France. These are roads full of traffic but they can increase the value of the facing real properties when they are conceived in relationship to the different urban functions that are present along the road and in relationship with the building and land typologies of the facing properties.
|the design of boulevards urbains in France||.||Definitely, the Act imposes the
use of the local land use plan to the City Councils to start any construction
(the POS, Plan d'occupation du sol). Finally, the definition of
the road and its environment is up to the architects, the town planners,
the landscape designers, and not only to the traffic engineers. This means
the responsibility of the building typologies, the alignments, the perspective
views, the green system of the boulevards and the avenues, if necessary
with the presence of the arcades, the pedestrian paths, the convivial public
spaces and the space reserved to parking, to local transit, the bicycles,
and the cars.
The interest is finally moved from the space of the road (roadway, benches and the sidewalks) to the space from the road (the road together with a large right of way that arrives to embrace, in France, the settlement system, the city, the landscape, and the adjacent buildings). Moreover, the perception of the road space and from the road is also proposed as a way to control the driver behaviour, to alert him and increase his attention, and therefore, as a mean to increase active safety.
|the New Urbanism in America||.||“An elevated index Veh*Km, Vehicles
for travelled Kilometres, is not always an indicator of economic vitality,
but, after all, perhaps it is an indicator of an economic and social dysfunction:
it points out that people are not where they would like or where they should
have to be”, Douglas Kelbaugh says, one of the theorists of the American
New Urbanism (Kelbaugh, 1997–p.
In America as in Europe, the New Urbanism movement has set centrally to the attention of the planner the need to reduce road traffic and the rate of growth of the mobility induced by non-sustainable settlements and land use models. On one hand The Principles of Ahwahnee, 1994, have in some way recalled the contents of a new “Athens Charter ”, of sustainable urbanism in local and regional communities. On the other hand they have pointed out the necessity of integration between the settlements system, transport infrastructures, land uses and the mix of functions, finalized to reduce the necessity of moving and to minimize resources consumption. They are also finalized to increase the value of local resources and of existing natural environment. The same indications are stated in Europe, in the official papers of the English government (DETR-UK 1999, Planning Policy Guidance 13. Transport).
|TOD, transit oriented development||.||The American movement of New Urbanism, recovering the legacy of the European rationalist urban planning, proposes planning choices and the design of TOD, Transit Oriented Development, which are structured around the lines of public transport, in order to reduce the necessity of mobility, to increase the quota served by modal alternatives to the private car, and to integrate urban functions (Calthorpe 1993, Kelbaugh 1997).|
|design guidelines||.||The most interesting part of this experience is, nevertheless, the communicative form of the plan, that uses the synthetic graphic language of the Design Guidelines. The purpose is to replace the zoning regulations, complex, prescriptive and restrictive, written from the lawyers and the bookkeepers of the urbanism, with the design guidelines for planning, mostly in graphic format, suggestive of the principles and of the criteria of planning, able to render explicitly, immediately, and in a general manner, the relationship between land use choices, infrastructures and architectural typologies in an area.|
|planning in Italy||.||In Italy indeed, we miss a planning
tool able to set in relationship the urban policies and the transport policies,
above all at the Municipality level that is the most effective level of
the planning. The most important tools, the Structure Local Plan (PRG)
and the Urban Traffic Plan (PUT), are dealt only with the physical planning
or only with the short management of the traffic. The integration between
the plans is almost always limited to a declaration.
The land use plan, which could be very useful for setting in relationship the building permits and land uses with the availability of the different modes of transport, almost always gives up any direct indication, and it sends back, for strategic choices, to other more authoritative hierarchically superior plans, as the Transport Plan and the Regional Structure Plan. But these are competence of other corporate body (Province or Region), they have times, finality and forms of control different from those of urban planning and, operating at regional level, they are ineffective to control the real land use and the management of the mobility system.
|the land use transport integration planning (MTTPR e PTLV)||.||In some planning experiences in other countries (MTTPR 1985, Toronto Canada–PTLV 1995, Locarno Switzerland) it is the Transport Regional Plan that analyses the possible land use alternatives in the planning document (the settlement models and the location of residences, places of employment and services, in the different physical forms of centripetal, linear, radiocentric, bipolar, dispersed city…). Such alternatives are compared to the available transport alternatives (the choices of infrastructures and of management: highways, arterial roads, subways, LRT lines, express bus, interchanges…). The most coherent combinations of association between land use choices and transport choices are compared according to a series of evaluation criteria (characteristics of transport demand, costs, socio-economic effects of the choices, environmental impacts, effects on the growth model, phases and feasibility of the model). The evaluation gives a classification of the available alternatives, the analysis of the consequences of each of the choices, and the identification of the interrelations between chosen land use model and choices of transport, in a rational and transparent approach to the planning process.|
|sustainability in local plans||.||Nevertheless, at local level in
Italy planning is moving in the direction of sustainability, that is towards
the integration between transport and land use policies and the evaluation
of the effects of new developments on the mobility; although national regulations
for traffic reduction and specific policies for traffic calming neither
specific technical norms have not been issued yet.
The updating of these regulations and the setting-up of manuals and design guidelines for planning has been one of the contributions of the MURST search on this theme. (Archivio Normative WebStrade su CD ROM, 1999-2000).
problem of common language
in the Italian paper
|.||In the second part of the article the importance of regulations and standards for the development of innovation and quality in the design of roads is analysed, giving the results of a national research (3).|
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