Transport and Spatial Organization
Author: Dr. Jean-Paul Rodrigue
1. The Spatial Organization of Transportation
Throughout history, transport networks have structured space at different
scales. The fragmentation of production and consumption, the locational
specificities of resources, labor and markets generate a wide array
of flows of people, goods and information. Transportation not only favors
economic development but also has an impact on the spatial organization.
Space shapes transport as much as transport shapes space, which is a
salient example of the reciprocity of transport and its geography. This
reciprocity can be articulated over two points:
- This relationship concerns the transport system itself.
Since the transport system is composed of nodes and links as well
as the flows they are supporting the spatial organization of this
system is a core defining component of the spatial structure. Even
if streets are not the city, they are shaping its organization in
terms of locations and relations. The same apply for maritime shipping
networks, which are not international trade, but reflect the spatial
organization of the global economy.
- This relationship concerns activities that are all dependent
on transportation at one level or another. Since every single activity
is based on a level of mobility, they relationship they have with
transportation is reflected in their spatial organization. While
a small retail activity is conditioned by local accessibility from
which it draws its customers, a large manufacturing plant relies
on accessibility to global freight distribution for its inputs as
well as its outputs.
The more interdependent an economy is, the more important transportation
becomes as a support and a factor shaping this interdependence. The
relationship between transport and spatial organization can be considered
from three major geographical
scales; the global, the regional and the local.
2. Global Spatial Organization
At the global level, transportation supports and shapes economic
specialization and productivity, through international trade. Improvements
in transport are expanding markets and development opportunities, but
not uniformly. The inequalities of the global economy are reflected
in its spatial organization and the structure of international transport
systems. The patterns of globalization have created a growth in spatial
flows (trade) and increased interdependencies. Telecommunications, maritime
transport and air transport, because of their scale of service, support
the majority of global flows. The nature and spatial structure of these
flows can be considered from two major perspectives that seek to explain
global differences in growth and accessibility:
- Core / periphery. This
basic representation assumes that the global spatial organization
favors a few core areas that grow faster than the periphery. Differential
growth creates acute inequalities in levels of development. Transportation
is thus perceived as a factor of polarization and unequal development.
From this perspective, parts of the global economy are gaining,
because they are more accessible, while other are marginalized and
bound to dependency. However, this
trend can be reversed if international
transport costs are significantly reduced. This is evidenced by
the substantial growth of many Pacific Asian countries that have
opted for an export oriented strategy which requires good access
to global freight distribution. Consequently, the core / periphery
relationship is flexible and relative.
- Poles. Transportation
is perceived as a factor of articulation in the global economy where
the circulation of passengers and freight is regulated by poles
corresponding to a high level of accumulation of transport infrastructures,
distribution and economic activities. These poles are subject to
centrifugal and centripetal
forces that have favored geographical concentration of some
activities and the dispersion of others. The global economy is thus
based on the backbone of freight distribution, which in turn relies
on networks established to support its flows and on nodes that are
regulating the flows within networks. Networks, particularly those
concerning maritime shipping and air transportation, are flexible
entities that change with the ebb and flows of commerce while nodes
are locations fixed within their own regional geography.
The global spatial organization is a priori conditioned by its
nodality. Global flows are handled by gateways and hubs,
each of which account for a significant share of the flows of people,
freight and information.
Gateway. A location offering accessibility
to a large system of circulation of freight and passengers. Gateways
reap the advantage of a favorable physical location such as highway
junctions, the confluence of rivers, a good port site, and have
been the object of a significant accumulation of transport infrastructures
such as terminals and their links. A gateway is commonly an origin,
a destination and a point of transit. It generally commands the
entrance to and the exit from its catchment area. In other words,
it is a pivotal point for the entrance and the exit in a region,
a country, or a continent and often requires intermodal transfers.
Hub. A central point for the collection, sorting, transshipment
and distribution of goods for a particular area. This concept comes
from a term used in air transport for passengers as well as for
freight and describes collection and distribution through a single
point such as the “Hub and Spoke” concept.
Often through the principle of economies of agglomeration and notable
accessibility advantages a region can accumulate several major gateway
infrastructures, namely port and airport terminals. They can be characterized
as gateway systems (or regions)
that play a substantial role in the global distribution of freight,
connecting major systems of circulation.
Services are following a spatial trend which appears to be increasingly
different than of production. As production disperses worldwide to lower
cost locations, high level services increasingly concentrate into a
relatively few large metropolitan areas, labeled as
world cities. They are centers
for financial services (banking, insurance), head offices of major multinational
corporations, nexuses for the arts and the seats of major governments.
Thus, gateways and world cities may not necessarily correspond as locations
underlining the ongoing dichotomy between central places and transport
places. This is particularly the case for containerized traffic which
is linked with new manufacturing clusters and the usage of intermediary
hubs.
3. Regional Spatial Organization
Regions are commonly organized along an interdependent set of cities
forming what is often referred as an urban system. The key spatial
foundation of an urban system is based on a series of
market areas, which are a
function of the level of activity of each center in relation with the
friction of distance. The spatial structure of most regions can be subdivided
in three basic components:
- A set of locations of specialized industries such as
manufacturing and mining, which tend to group into agglomerations
according to location factors such a raw materials, labor, markets,
etc. They are often export oriented industries from which a region
derives the bulk of its basic growth.
- A set of service industry locations, including administration,
finance, retail, wholesale and other similar services, which tend
to agglomerate in a system of central places (cities) providing
optimal accessibility to labor or potential customers.
- A pattern of transport nodes and links, such as road,
railways, ports and airports, which services major centers of economic
activity.
Jointly, these components define the
spatial order of a region,
mostly its organization in a hierarchy of relationships involving flows
of people, freight and information. More or less well defined urban
systems spatially translate such development. Many conceptual models
have been proposed to explain the relationships between transport, urban
systems and regional development, the
core-periphery stages of development
and the network expansion being among
those. Three conceptual categories of regional spatial organization
can be observed:
- Central places / urban systems
models try to find the
relationships between the size, the number and the geographic
distribution of cities in a region. Many
variations of the regional
spatial structure have been investigated by the Central Place Theory.
The great majority of urban systems have a well established hierarchy
where a few centers dominate. Transportation is particularly important
in such a representation as the organization of central places is
based on minimizing the friction of distance. The territorial structure
depicted by Central Place Theory is the outcome of a region seeking
the provision of services in a (transport) cost effective way [Preston,
1985].
- Growth poles where economic development
is the structural change caused by the growth of new propulsive
industries that are the poles of growth. The location of these activities
is the catalyst of the regional spatial organization. Growth poles
first initiate, then diffuse, development. It attempts to be a general
theory of the initiation and diffusion of development models. Growth
gets distributed spatially within a regional urban system, but this
process is uneven with the core benefiting first and the periphery
eventually becomes integrated in a system of flows. In the growth
poles theory transportation is a factor of accessibility which reinforces
the importance of poles [Perroux, 1955].
- Transport corridors represent an accumulation of flows
and infrastructures of various modes
and their development is linked with economic, infrastructural and
technological processes. When these processes are involving urban
development, urbanization corridors are a system of cities oriented
along an axis, commonly fluvial or a coastline. Corridors are also
structured along articulation
points that regulate the flows at the local, regional and global
levels either as hubs or gateways. Historically, urbanization was
mainly organized by the communication capacities offered by fluvial
and coastal maritime transportation. Many urban regions such as
BosWash (Boston - Washington)
or Tokaido (Tokyo
- Osaka) share this spatial commonality.
4. Local Spatial Organization
Although transport is an important element in rural spatial organization,
it is at the urban level that transportation has the most significant
local spatial impact. Urbanization and transport are interrelated concepts
(see Chapter 6 for a detailed
perspective concerning urban transportation). Every city relies on a
need for mobility of passengers (residence, work, purchases, and leisure)
and freight (consumption goods, food, energy, construction materials
and waste disposal) and where the main nodes are employment zones. Urban
demographic and spatial evolution is translated in space by the breadth
and amplitude of movements. Employment and attraction zones are the
most important elements shaping the local urban spatial organization:
- Employment zones. The growing dissociation between the
workplace and the residence is largely due to the success of motorized
transport, notably the private automobile. Employment zones being
located away from residential zones have contributed to an increase
in number and length of commuting trips. Before suburbanization,
public transit was wholly responsible for commuting. Today, the
automobile supports the majority of these trips. This trend is particularly
prevalent in highly populated, industrialized and urbanized zones,
notably in North America and Western Europe, but motorization is
also a dominant trend in developing countries.
- Attraction zones. Attraction zones linked to transport
modes are areas to which a majority of the population travels for
varied reasons such as shopping, professional services, education
and leisure. As with central place theory, there is a certain
hierarchy of services within an
urban area ranging from the central business district offering
a wide variety of specialized services to small local centers offering
basic services such as groceries and personal banking.
The development of cities is conditioned by transport and several
modes, from urban transit to the automobile, have contributed to the
creation of urban landscapes. Three distinct phases can be noted:
- The conventional/classic city. Constructed for pedestrian
interactions and constrained by them, the historic city it was compact
and limited in size. The emergence of the first public transit systems
in the 19th century permitted the extension of the city into new
neighborhoods. However, pedestrian movements still accounted for
the great majority of movements and the local spatial organization
remained compact. Many European and Asian cities still have a significant
level of compactness today.
- Suburbanization. The advent of more efficient public
transit systems and later on of the automobile permitted an increased
separation of basic urban functions (residential, industrial and
commercial) and the resulting spatial specialization. The rapid
expansion of urban areas that resulted, especially in North America,
created a new spatial organization, less cohesive than before but
still relatively adjacent to the existing urban fabric. Although
this process started in the early 20th century, it accelerated after
the Second World War.
- Exurbanization. Additional improvements in mobility favored
urban expansion in the countryside where urban and rural activities
are somewhat intermixed. Many cities became extended metropolitan
regions, with a wide array of specialized functions including residential
areas, commercial centers, industrial parks, logistics centers,
recreational areas and high tech zones. These exurbanization developments
have also been called "edge cities".
The automobile has clearly influenced contemporary spatial organization
but other socioeconomic factors have also shaped urban development such
as gentrification and the increase in
land values. The diffusion of the automobile has lead to an urban
explosion. The car has favored the mobility of individuals thus permitting
a disorderly growth and an allocation of space between often conflicting
urban functions (residential, industrial, commercial). Transport thus
contributes to the local spatial organization, however, it must also
adapt to urban morphologies. Transport networks and urban centers complement
and condition each other.
Media

Scales of Spatial Organization for Transportation

Center / Periphery Division of the World

Impact of Transport Cost Reductions on Inequality

Poles of the Global Economy

Forces of Geographical Concentration and Dispersion

Gateways and Hubs

Modal Gateways

Major North American Gateways, 2007
(Detailed PDF map)

World’s Major Gateway Systems, 2006
(Detailed PDF map)

World Cities, 2008
(Detailed PDF map)

The Spatial Order and Transportation

Main North American Trade Corridors, Gateways and Inland Freight
Clusters
(Detailed PDF Map)

Delimitation and Variations in Market Areas

Central Places and Transport Places

Central Places Theory

Market Size / Area Relationships in the Central Places Theory

Variations of the Central Places Theory

Urban Hierarchy

Growth Poles Theory

Core-Periphery Stages of Development in a Urban System

Corridor Development

Modal Corridors

Articulation Point and Freight Distribution

Transport Corridors and the Regional Spatial Structure

The BostWash Corridor
(Detailed PDF Map)

The Tokaido Corridor

Land Use Values and Activity Sectors

Central Places in Urban Areas