Chapter 1 Introduction

The Athens Charter proposes four basic activities of the city - living, working, recreation and transportation. The figure shows the basic relationship between the four basic urban activities and the urban land use structure and the urban transportation system. Four basic activities of city like live, work and recreational activities are to be carried out in a fixed place and each has a fixed target, the arrangement of land use is the absolute land use, and the reciprocal relationship between them is the relative land use between each other, from the position and quantity relationship of urban land layout structure, reflects the static function relations of the city.

Buchanan's vision of a comprehensive urban design, led by transport, repurposed part of London into a vast mega-structure that vividly illustrates the“new urban form”that motor vehicles demand. Among other things, this envisages the city's urban highways and multi-storey car parks, towers and pedestrian platforms set up in the maze system of distributor roads and underground services. It was noted that this approach was“almost revolutionary”, but in fact the design was later highlighted as“the revolutionary, even disastrous, impact of modern transport planning on the form of towns”.

Today, both transport and urban design have a high profile, and their conjunction increasingly appears crucial to contemporary planning. This thesis sets out to explore how transport provision can be used towards urban structuring and hence the design of urban areas. In doing so, it cannot avoid the legacy of Traffic in Towns, nor the intervening reactions against its revolutionary impact.

It turns out that urban design methods dominated by highway design are“disastrous”. In urban areas, the actual consequences of highway projects are not limited to the destruction of existing urban structures, such as invasion, separation, demolition and wither, which can be collectively referred to as urban destruction. They also include the negative effects of highway engineering as a formative urban layout. In fact, this means that the methods of highway design tend to lead to monotonous or dysfunctional layouts, resulting in a lack of identity, vitality or urbanity in new development. Although the cost of urban destruction is tangible, it is also an opportunity to create more ideas in the design and create a good urban environment.

The loss engendered by this creation would be all the more tangibly felt here, due to being directly juxtaposed with an existing, functional city quarter. A bustling commercial street, would be transformed into a multilane motorway, terraced and flanked on either side by parallel collector-distributor roads, forming a traffic canyon some 100m wide, apparently accommodating a dozen lanes of traffic. Its four level intersection would occupy an area that could accommodate a hospital or university.

Such retrofits are hardly considered today. Even by the early 1960s, the wisdom of integrated redevelopment, traffic-led urban design and top-down planning was questioned, which Jane Jacobs linked to the failure of urban planning. Christopher Alexander then similarly questioned the strict simplicity of a hierarchical urban system.

In Buchanan's case study of design, the overlap between the street energy that Jacobs pursued and the urban life that Alexander pursued would disappear. Tottenham Court Road's role as a ‘seam'between the cities of Fitzrovia in the west and Bloomsbury in the east will be lost as these areas will be separated and isolated. Shops will be stuck on the deck of the sidewalk, far from passing trade. Buses will be packed in the middle of the regional distributor level. The familiar urban“pattern”of a grocery store next to a bus stop and a bar on the corner will disappear.

Today, of course, the rhetoric of the ‘motor age'has been replaced by the rhetoric of sustainability and New Urbanism. Sustainable transport modes and neo-traditional street patterns are in vogue. The ‘monolithic modernism'of highway engineering and car-oriented urban'solutions'are on the back foot.

However, Buchanan's basic blueprint is: the core principles of layout and the“hierarchy”of roads, and positive relational functions, urban morphology and structure, living in current theory and practice. His design idea is not only to coordinate the urban traffic, but also to put forward the basic blueprint of the urban structure based on the traffic system, showing the possibility of“traffic architecture”. In a big sense, we still build towns like this.

The UK's housing development in 1999 exceeded expectations and its expanding needs urgently needed to reconcile the aspirations of contemporary urbanism with the functional structure of transport supply. This poses a challenge for all designers: it's not just about where to build new housing, it's about all the design forms associated with it.

Yet, despite present good intentions to prioritize sustainability, and the desire（at least among urbanists）for a return to more traditional urban forms, achieving these is not straightforward. While the destruction of central London might no longer be contemplated, it would be difficult to actually create a Fitzrovia or a Tottenham Court Road today. We could not create the exemplary urbanity of traditional cities such as London.

This, then, represents the stimulus and the challenge set for the research. Accordingly, this thesis will examine relationships between transport and urban structure, and hence explore how transport can contribute positively to the structuring of urban areas in a way appropriate to today's needs. This means reconciling the functional needs of traffic with those of sustainable transport modes and with wider urban design objectives. In doing so, the thesis must go beyond the rhetoric of contemporary urbanism, to the root of the urban structural problem, and develop an approach which can address today's ends.

1.1 Objectives

The particular concern of the thesis is the contribution of transport provision to urban structure, and hence the physical layout of urban areas. This focus on the structure of cities, and the transport structure at that, may be regarded as the definitive scope of the thesis. The research can ultimately contribute to the better design of cities, although the approach of this thesis represents just one possible way of doing so. Within the chosen scope, however, a substantial exploration is possible, and a clear sequence of objectives and sub-objectives may be identified.

These themes are the urban design centered on the urban structure proposed by the Shanghai cooperation organization, and the physical layout provided by transportation.

Therefore, our purpose is how to design the urban structure, especially the layout of residential area in the transportation network paper.

How does transport relate networks be structured to urban structure？

What are the desired? By what means should properties of network transport-constituted urban structure？

How to describe network? How to explain existing urban structure？

How has desirable urban network forms relate to structure traditionally been urban functions?In chapter 1, our goal is divided into two concerns: the relationship between traffic and urban structures, and the structure of transportation networks. The traffic network structure further solves the expected attributes of the urban structure and the methods to realize these attributes by design. These, in turn, raise several more specific questions about describing and interpreting network structures. Although these more detailed questions do not need to be explicitly raised at the beginning of the investigation, they will be effectively presented during the study, and they play an important role in linking the arguments and influencing the arguments.

In fact, our research can be viewed in two distinct but intertwined ways. The first part is the“design debate”which has to do with contemporary concerns such as how to integrate transport supplies and urban design, what urban structures are desirable, and how to design them. The second part is an in-depth investigation of“the nature of the urban structure”, what it is, how it is described and analyzed, and how it explains the observed structure.

In a sense, urban structural design is included in the overall debate on urban design. The urban structure is a relatively abstract and theoretical part, while the design debate is more directly related to the contemporary design environment. The debate of design idea gives the purpose and relevance of urban structure survey, while urban structure provides some“solutions”for urban design and provides information basis for the debate of design idea.

The research topic is described and discussed from the whole urban design, which is integrated into the whole design concept structure. The chapters are interrelated, rather than an independent discrete theme.