The Sustainable city, C.A. Brebbia A. Ferrante, M. …...The Sustainable City 365 geographical...

The sustainable street - major premises for

street design

E. Lillebye

Norwegian Public Roads Administration

Abstract

Traditionally the street has served as an arena for activities covering a blend offunctions and traffic forms. However, throughout the last 50-70 years we havemoved away from this by introducing the urban segregated traffic system. Forsome decades, the consequences of traffic separations have been questioned, andthe problem crassly worded: "Are car-free cities the best ones?" In severalcountries large funds are being spent on reconstructing cities and urban areaswith a view to improvement of traffic solutions as well as the conditions formeeting places and social life. As the street might be regarded as "the pulse ofthe city", it is of vital importance that the street regain its position as the maincommercial and social arena of the traditional city. A city is dependent uponsustainable streets to become sustainable itself, streets that can meet theincreasing demand from the public regarding activities and offers. In doing so,the city administration has to act strategically in a long-term perspectiveaccording to a plan that incorporates the various aspects of street design;architectural, functional and social. This planning approach necessitatesunderstanding and respect across the various professions that claim the streets aretheir special field of interest.

The Sustainable city, C.A. Brebbia A. Ferrante, M. Rodiguez & B.Terra (Editors) © 2000 WIT Press, www.witpress.com, ISBN 1-85312-811-2

362 The Sustainable City

1 Introduction

Apart from being a transport artery, the street, including squares and otherexternal public spaces, has through history had an important role as the mainurban arena for exchanging goods and merchandise and for human activities,both socially and politically. This fact was totally neglected by the modernists.Le Corbusier went as far as to renouncing the historical street by stating: "Ourstreets no longer work. Streets are an obsolete notion. There ought not to besuch a thing as a street; we have to create something that will replace them".And the functionalist did just that by inventing the urban motorway, deprived ofall the qualities of the historical street that is so appreciated today. Functionalismdid not only restructure the historical urban pattern and create the suburbia -"theland between"-, it also wiped out two generations of street planners, leaving theart of street design, by both architects and transport planners, in a deplorablestate of incompetence. Even today, many streets in new urban developmentprojects seem to have purely one purpose beside its traffical function, namely asa mere divider between buildings, rather than being designed to fill a role as acommercial and social arena. As street planning (as well as urban planning ingeneral) has become a sectorized discipline, meaning that planning has beensegregated into separate fields of interest with their own professional expertise,the ability to co-ordinate the multitude of functions of the street into an overallplan has been strongly reduced. The premises for street design differs naturallyaccording to local conditions and variable functional requirements, but they arerarely considered coherently. The criteria for "a good street" reflects this fact.The definitions of the "good street" are as versatile as the apprehensions of themanifold of users. To create the common "good street" however, all the aspectsof the street has to be appraised and subsequently given preference. In order toestablish such criteria, several conditions have to be considered. Theseconditions vary from overall conditions to physical characteristics, offers andaccessibility.

2. Overall conditions

Overall conditions comprise a range of elements, and are defined as externaldesign prerequisites which are distinct from, but influential upon, the localfunctional and architectural characteristics of the street. Environmental strainscaused by traffic, such as noise and air pollution, traffic accidents and generalcrime are elements which are defined as overall conditions. Furthermore, thegeneral development and transformation of land use, might also have a greatimpact on the local planning of the street. Overall conditions may alter overtime, but very differently. As climate and cultural conditions might beconsidered as static, demographical conditions and land use are subject forchanges due to political initiatives. Local strains, however, are more sensitive tochanges.


The Sustainable City 363

2.1 Climate

Climatical conditions have always had a strong influence on the location andlayout of public spaces. The physical form of streets and squares has either beendesigned to provide shelter against sun and rainfall or to promote theaccessibility of the sun, depending on the geographical location. While theinhabitants of equatorial countries through centuries have developed physicalarrangements to reduce the impact of the sun, the people of the arctic countrieshave implemented the quite opposite provisions. Such arrangement vary fromthe location and layout of urban structures, to the design of the street scape, fromthe placing of street furniture to the colours and details of buildings. Rain andsnowfall, wind, temperature and availability of sunshine are meteorological datawhich are essential premises for the design of public spaces. Climaticalconditions constitute, for instance, one of the success criteria of the shoppingcentres, ensuring people stable and pleasant weather conditions at all times. Insome countries this kind of planning approach has been developed to theextreme. In some American and Asian cities the traditional streets have becomedesolated, replaced by underground walkways and elevated tubes linking oneshopping centre to another. In Bod0, a town in the north of Norway, the mainstreet has been fully glassed as protection against the heavy rain and snowstormsof the North Sea. The result is that the original main public space of the city hasbecome privatised and unavailable to the public outside opening hours.

2.2 Urban culture

"Urban culture" is a relative notion, but can be described as an urban cultureinheritance based upon identity, customs and tradition. Such urban culture varywithin the Western society, and is linked to the way the different countries haveorganised their social and mercantile communities throughout history. While thesouth- and central European farming communities were developed as centralisedclusters with the fields situated radiating from them, the farms of the Nordiccountries constituted independent units divided by agricultural land and forests.Consequently, south and central Europe developed early a dense urbancommunity, such as the English "village" and the German "dorft", based on asocial awareness and a common and shared respect for the public space. InScandinavia and particularly in Norway, the lack of urban tradition has resultedin a disrespect for the public space and a fanatic interest in the interiors. "Whilewe are leaving the development and design of cities, squares and streets tochance, we are exceedingly careful that the style, colours and materials of ourprivate sphere go well together, and that the interior of our home gives a neat,pleasant and inviting impression. The kitchen and the basement sittingroom areour sights. It is the interior of our home that we are proudly presenting toforeign guests after having carried them past the road junction and the adjacentpizza bar that make up the core of the village centre" .



Despite geographical location, the ownership and awareness of the commonurban space have great influence on the use of streets and squares of the city.This cultural approach might take various forms and result in different types ofurban life, especially today when many major cities have a cultural mix amongtheir inhabitants. Consequently, both the original and the new urban culture, orthe soul of the local community, should be appraised and recognised as vitalpremises for all types of planning initiatives. These types of premises can befound in textbooks, but are best obtainable by the inhabitants themselves, whothrough experience of life can supply the planner with indispensable informationabout the characteristics of the use of the local public space.

2.3 Demography

Demographical conditions are strongly influential on both functional and socialcharacteristics of streets. Traditional streets are primarily situated in the citycentres which have other age groups than for instance the suburbs. As thesuburbia was established in the 1970s and onwards, the demography of theWestern city centres as a whole changed. From having a high proportion ofdwellings, many city centres have become commercial arenas, comprising shopsand offices. In such city centres, the activities of the street are primarilydependent upon the opening hours of the various commercial functions.Consequently some city centres are basically derelict after 5.00 PM.

In city centres with some infusion of dwellings, the family and age structure ofthe inhabitants have changed dramatically. From being inhabited by all familytypes, the one person family has became the typical dweller of the city centre.The age structure has changed accordingly. Recent research in Norway (1996)have established that compared with the suburbs, the city centre has a smallerportion of children under the age of 20, a higher portion of the age group 20-29,a lower potion of the age group between 30 and 66, an equal portion of the agegroup between 67 and 79, and a higher portion of inhabitants over the age of 80.These data correspond well with the demographical trends in the Western world.As the new established families move to the suburbs where the detached familyhouse allures at a reasonable prize, the young generation stays behind, enjoyingthe social and active life of the urban street. In addition to this statistic fact, thereseems to be more unregistered young people living in city centres, such asstudents attending local colleges and universities.

2.4 Environmental strain

Environmental strain represents today a major challenge. Its effect is general buthas different individual and local implementations. The human threshold toaccept noise and air pollution varies from person to person dependent upon the



geographical location, the social status and the aesthetical quality of the physicalenvironment of their local community in addition to the physiological conditionof the individ. There is a tendency, indicated by recent research in Norway, thatpeople are willing to accept a high level of noise and air pollution within theurban public arena on the assumption that it offers a variety of qualities to thepublic. The "Avenue Champs Elysees" in Paris has an average traffic flowexceeding 100.000 cars a day. Despite this extreme level of traffic, the boulevardis probably the greatest tourist magnet in France, with so many non car users thatthe pedestrianized area recently has been considerably expanded. It is thearchitectural splendour, the greenery, the offers, the history and the individualityof the " Avenue Champs Elysees" that constitute its attraction - and above all theusers themselves. Thus, the effect of environmental strains as a threat towardsthe liveable and sustainable street is difficult to measure. The "environmentalcapacity" of streets is dependent upon a versatility of conditions beyond noiseand air pollution, although these two elements hardly without exception aresubject to extensive attention and research as major sources for theenvironmental downgrading of the street. This is due to the fact that noise andair pollution are physical quantities, as opposed to qualitative quantities such asaesthetic and social characteristics, and are easily measured.

2.5 Crime and traffic accidents

Crime and traffic accidents are the condition that creates most fear and insecurityamong street users. There is no doubt that crime at present is the most publishedphysical strain of the city, but statistics show that street users are generally morelikely to be knocked down by a car than by a fellow human being. Furthermore,the persons that are less likely to be involved in unprovoked violence, females inthe agegroup 20-40, are the ones feeling most insecure. Likewise, the males inthe same agegroup have little fear of street violence although they are the groupmost likely to be involved. The insecurity and emotional attitude towards crimeand traffic accidents among urban inhabitants, do not seem to correspond withstatistical facts. However, both traffic accidents and street violence arefrightening realities to urban inhabitants in the industrial world. Traffic accidentscan be prevented by restrictions and physical regulations. The segregated trafficplanning model created dissolved cities, but also reduced the number of trafficaccidents considerably. The "0-vision" of the Nordic traffic security programme,indicating a future aim of no fatal traffic accidents, might be consideredunrealistic, but nevertheless illustrates the faith in traffic management as a tool toreduce traffic accidents.

Crime, however, is hardly manageable through physical means. Crime andviolence is undoubtedly a major problem within the urban society, and toestablish "the safe city" represents an immense challenge. Planners have throughcenturies strived to arrange the urban physical environment to encourage a



civilised intercourse between human beings. Consequently, the public space hasoriginally been designed to prevent crime, not to provoke it. What themodernistic urban planners ignored however, was the fact that a city is notconstituted by monumental buildings but the space between such architecturalelements; and furthermore, the social significance of the intermediate zonebetween the public and the private arena: "A bookseller who displays books onthe pavement outside his shop, has extended his private sphere by borrowing abit of the public arena. A cafe owner who has placed two tables on the pavement,indicates that the public space continues into his premises. Such signals regulatepart of the social life of the city and they express the function and the social useof its buildings ".

3. Physical characteristics

The physical characteristics of the street comprise the architectural andaesthetically significance of the street scape including buildings, furniture andvegetation. These elements are important factors in order to establish thesignificance of physical form as a condition for urban life. How the physicalenvironment is influencing the street as a social arena is a matter of professionaldissension. As the architects emphasise high architectural and aesthetical qualityof the built environment as the major condition for a liveable street, thesociologists claim otherwise. However, physical planning has during centuriesproved to have a great influence on the quality of the social conditions of theurban society, both negatively and positively. Therefore, the characteristics ofthe physical environment represents an important planning premise.

3.1 Street scape

The street scape might be described as the three dimensional characteristic of thestreet comprised by the street dimension, the characteristics of the street withinthe urban structure, the land use of the street, the use of materials and the level ofmaintenance. The street dimension, is defined as the ratio between the width ofthe street floor and the height of the vertical elements, usually comprised bybuildings or vegetation, or both. This ratio indicates the spatial characteristics ofthe street, architecturally differentiated between the narrow alleys of theMedieval and the broad boulevards of the Baroque. Each architectural trend hasdeveloped their own definition of the optimal street dimension, and numeroustheories, for instance represented by Camillo Sitte and the Krier brothers, givedescriptions of the three-dimensional significance of the street scape, or its"architectural dynamics".

3.2 Buildings

The notion "built form" comprise the structural arrangements of the building



blocks as well as the individual peculiarity of buildings such as architecturalcharacter and maintenance. Urban structures can assume different architecturalforms dependent upon local geographical and topographical conditions andfunctional requirements, in addition to ever changing planning ideals.Consequently, the appraisal of the structural characteristics of the urban formmust not be generalised, but be based on local conditions. Such knowledge is ofvital importance to comprehend the layout of streets, described through theirlinear and perpendicular characteristics, both vertically and horizontally. Theaesthetical quality of the built form in general, and of the public space inparticular, is in most cases derived from an architectural intention and how thisintention is realised and maintained. Each street has its specific architecturalidentity, based upon its symbolic individuality and prevailing architectural stylesand trends. Such architectural identity reflects the hierarchical position of thestreet within the urban structure, both functionally and architecturally andindicates social and cultural status. This is, along with the architecturalcharacteristics of the street scape, expressed by the architectural scale, the height,the colour, the elements and the detailing of buildings. It is difficult to find abetter example to illustrate this than the Victorian building tradition in Britain,where for instance the architectural expression of the housing symbolised thewaste difference in status within the social community.

The level of maintenance reflects architectural ambition and status and thecultural awareness of the local community to regard the public space as aresidential arena. The Italians, who do not even have the notion "home" in theirvocabulary, have an altogether different attitude towards their common areascompared to most Europeans. As their dwellings remain a arena for the triviallife of the family, the put a lot of energy in the upkeeping and maintenance in thepublic space, because when the "piazza" fulfil the function of the local sittingroom, there is no need to put much time, money and effort to touch up therelatively simple housing standard. The English "pub" and the German"bierstube" have all the same function and social quality.

3.3 Street furniture

Architecturally, public furniture are underestimated elements within the publicurban space. Street furniture, both commercial and technical, has an immensevisual impact on the aesthetical quality of the city - and the street. The visualcharacteristics of the public space is far more than buildings and the physicalspace between them. It is also constituted by the multitude of technical andfunctional elements. Such elements have generally different origin, both privateand public, and are often implemented without apparent co-ordination, even bymembers of the same institution. Elements, such as for instance trafficalequipment, lighting, masts, benches and not least advertising, are in most casesplanned independently from the general built environment, often accidentally



selected on the basis of the product catalogues the planner might have at hisdisposal at a given time. A well considered layout of street furniture is not only acondition to achieve public arenas of high aesthetic quality, but also to promote apositive social use of the common space. Benches are for instance not onlyelements of architectural importance, but actually facilities for seating andsocialising. Consequently, benches should be arranged in such way that theirusers benefit from both the activities of resting and taking part in the social lifeof the street: to see and to be seen. A bench which does not meet the lattercriterion is rarely used. Such planning criteria are often too inevitable to enterthe mind of the rational planner, who often gives preference to architectural andtechnical requirements rather than to the needs of the irrational common user.

Another element with both social and architectural significance is lightning.Lighting has during the 20* century been an important policing element of thecity, extending the use of its facilities considerably, especially in the Nordiccountries. It is no coincidence that the Norwegian town Hammerfest, thenorthernmost city in the world, was the first town ever to develop an overallelectric street lighting system, enabling its inhabitants to use the city fully duringthe six months of darkness. Apart from the apparent functional advantages oflightning, it has architectural features beyond recognition. Many recent lightdesign projects, for instance in France, have through a high level of technology,illustrated the magnificence of lighting both as an individual architecturalelement, as sculptural art and as an accentuating complementation to the visualsignificance of buildings and constructional elements. However, few architectsand transport planners are aware of the possibility of light as a design tool. Streetlightning are in most cases still planned according to technical road designmanuals, ignoring the secondary light sources from shops, restaurants and soforth, leaving the streets in a glare.

Today, a lot of attention is concentrated in the achievement of preventingvandalism and aesthetic depreciation of the public space. As street furniture isthe most accessible urban element with regard to vandalism, the publicmanagement of such elements is an important contribution to this joint effort.Local street design manuals and appraisal programs are being published in thehope to incorporate the various street elements within the overall physicalenvironment of the public space. The main challenge however, is to change thepresent conduct towards industrial design, and introduce this special field ofinterest as an integrated part of street design.

4. Offers

As the aesthetic quality of the physical environment undoubtedly is a majorcondition for a liveable street, sociologists regard the manifold of offersprovided by the city as equally, or probably more important. Architectural



features and social activities might be regarded as offers themselves, butfunctions like commerce, services, catering and culture have always influencedurban life and been the very condition of the foundation of cities. The appraisalof the street as a social arena must therefore include thorough studies of suchfunctions to become expedient. The "multitude of functions" have always beenregarded as the significance of the city centre and the street. During the pastdecades however, this characteristics has been exploited fully in the developmentof the shopping centres, which today can offer a complete range of functionssimilar to the traditional street, including cultural and recreational facilities. Sohow can the street compete? In order to vitalise the city centre and retract theconverted user of the shopping centre back to the street, the commercialassociations of the city must adapt the administrative organising system of theshopping centres in order to strengthen the co-operation and management amongshop owners, and promote the specialised shops which represents an offer notprovided by the suburban centre. Furthermore the city administration has tocultivate the offers that the centres can not provide, namely the cultural identity,the history, the unpredictability and the availability of the urban street which.

5. Accessibility

Accessibility is rated as a major condition for a liveable street. It is however, arelative notion, dependent upon other characteristics of the street, such asdemography. Shop owners claim that poor accessibility by car represents ageneral course for the decline in the commodity trade of the city centre. Thisaccusation might bee right, but only for non-residential streets with poor or noaccess to public transport. Research has indicated that the users of shoppingstreets within residential urban areas, or in areas with a well developed publictransport system, rarely use the car as a mean of transportation. Accessibilitymust therefore be regarded as a consequence of land use and alternative transportfacilities than the car. The key to improve the accessibility within the city centreis therefore to vitalise it by altering the land use in favour of residential purposes.Urban housing facilities is a condition for a liveable city, and for a liveablestreet. Today there is a tendency to reverse the commercialisation of the citycentre, by promoting urban housing or even transforming commercial buildingsinto flats. To increase the proportion of housing within the city centre is animportant part of the vitalising of the city, which is a major goal for many citycouncils today. In this vitalisation process the politicians and planners have torecognise the street as the pulse of the city, and the streets has to becomeaccessible for both local inhabitants and people from the suburbs.

6. The challenge of future street planning

Reestablishment of the traditional street as an alternative to the privatised



corridor of the shopping centre, necessiate a joint effort from a wide specter ofprofessionals which all claim the street to be their special field of interest.Although, physical planning has influenced urban life during centuries, a recentresearch of the attitudes of street users in four Norwegian cities (1996), detectedno indication that the quality of the physical environment had any affect on citylife. It is also difficult to identify the reasons why people prefer one particularstreet to another as an arena for social activity. However, the registrationsindicated that:• the more applied functions the street has to offer, the greater is the soscial

activity• the total number of shops, create a variation of the use of the street• service offers generate soscial activity• restaurants and other eating-facilities generate soscial activity• the accessibility of cars does not seem to be of decisive importance to social

activity; the accessibility for cars to the city centre seem to be more important• the accessibility for public transport has a great significance to social activity• the accessibility for pedestrians to and within the city center is of decisive

importance to social activity• the accessibility for bicycles is less important to social activity than the

accessibility for pedestrians• closeness to the main shopping area of the city center is of vital importance

to intepret the level of social activity in the city centre* area use affects city life; the size of the area reserved for pedestrians, the

number of shops and service facilities and the number of bus stops seem toaffect the social activity

• the weather conditions affects the socalled voluntary activities, such asstrolls, visits to outdoor restaurants and leasure biking, while socallednecessary activiteis, such as visits to the food store, does not seem to benoticeable affected

• heavy noise and a high level of air pollution does not seem to have anyreducing affect in areas that can provide attractive offers to the public

• traffical barriers (heavy traffic and fences) do seem to have an affect on theactivity behaviour as it reduces the freedom of movement

It is a general tendency that the are other conditions than the quality of thephysical environment that has decisive affect on social activity in streets.Conclusively, order to strengthen the street as a commercial and social arena thestreet planner has to:• emphazise the manifold of activities in the street• create good accessibility to and within the street

• reduce motorized traffic barriers to a level that it subordinates to thesocial activity


The Sustainable city, C.A. Brebbia A. Ferrante, M. …...The Sustainable City 365 geographical...

Documents

Transcript of The Sustainable city, C.A. Brebbia A. Ferrante, M. …...The Sustainable City 365 geographical...