Jean-Paul Rodrigue (2017), New York:
Routledge, 440 pages.
Authors: Dr. Jean-Paul Rodrigue and Dr. Claude Comtois
Transport geography is concerned with movements that take place over
space and the physical features of this space impose major constraints
on transportation systems, in terms of what mode can be used, the
extent of the service, its costs, capacity and reliability. Three basic
spatial constraints of the
terrestrial space can be identified:
From a geometrical standpoint, the sphericity of the earth determines
great circle distance; the least distance line between two
points on a sphere. This feature explains the paths followed by major
intercontinental maritime and air routes.
2. Overcoming the Physical Environment
Rapid technological developments have enabled transportation to overcome the physical environment.
Prior to the industrial revolution most road paths were adapted to
topography. Since then, efforts have been made for paving roads, bridging
rivers and cutting paths over mountain passes. Engineering techniques in
terms of arch and vault used in Byzantine and Gothic church
constructions in the twelfth century permitted bridge building across
wider streams or deep river valleys. Road building thus has been at the
core of technological efforts to overcome the environment since they are the support for local and even long distance travel. From
the efforts to mechanize road transport modes to the development of
integrated multilane highways, road building has transformed the
Innovations in maritime transport can be found around the world.
The earliest developments came in the transformation of waterways for
transportation purposes through the development of canal locks
coping with adverse
natural gradients. Further improvements in navigation came with the cutting of
artificial waterways. Some of the earliest examples can be found in
the Dutch canals, the Martesana canals of Lombardy, the canal de Briare
in France or the Grand Canal of China. Further improvements in navigation
technology and the nature of ships permitted to increase the speed,
range and capacity of ocean transport. However, the increasing size of ships
has resulted in excluding canals such as Panama and many ports from servicing
the largest ships. Several
port authorities have thus embarked in expansion programs.
Passages through the Arctic Ocean are being investigated with a
view to create new international connections. Artificial islands are
also created to permit port installations in deep waters.
As level ground over long distance is important for increasing the
efficiency of railway routes, the transport industry has come to modify
the earth’s features by building bridges and tunneling, by embanking
and drainage. From the early steam engines to the first high speed
motive power has permitted physical obstacles to be overcome by rail.
The role of technology has been determinant in the development of
the air transport sector. From the experiments of the Montgolfier brothers
to the advent of jet aircraft, aerial crossing of rugged terrain over
considerable distance became possible. Technical innovation in the aeronautic
industry has permitted planes to avoid adverse atmospheric conditions,
improve speed, increase range and raise carrying capacity. With
the rapid rise in air passenger and freight transport demand, emphasis has
been given to the construction of airport terminals and runways. As
airports occupy large areas, their environmental footprint is important.
The construction of Chek Lap Kok airport in Hong Kong led to leveling
mountainous land for the airport site. Kansai airport servicing Osaka
has been built on an artificial island.
3. Transportation and the Spatial Structure
The concepts of
site and situation are fundamental to geography and to transportation.
While the site refers to the geographical characteristics of a specific
location, its situation concerns its relationships in regard to other
locations. For instance, a port site relates to attribute such as
the suitability of its harbor while a port situation relates to its
connectivity with its foreland (other ports) and hinterland (the inland
market it serves). Thus, all locations are relative to one another but situation
is not a constant attribute as transportation developments change levels
of accessibility, and thus the relations between locations. The development
of a location reflects the cumulative relationships between transport
infrastructure, economic activities and the built-environment. The following
factors are particularly important in shaping the
- Topography. Features such as mountains and valleys have
strongly influenced the structure of networks, the cost and feasibility
of transportation projects. The main land transport infrastructures
are built usually where there are the least physical impediments,
such as on plains, along valleys, through mountain passes, or
when absolutely necessary through the digging of tunnels. Water
transport is influenced by water depths and the location of obstacles
such as reefs. Coastlines exert an influence on the location of
port infrastructure. Aircraft require airfields of considerable
size for take off and landing. Topography can impose a natural convergence
of routes that will create a certain degree of centrality and may
assist a location in becoming a trade center as a collector and
distributor of goods. Topography can complicate, postpone or prevent
transport activities and investment. Physical constraints fundamentally
absolute and relative barriers to movements. An absolute
barrier is geographical feature that entirely prevent a movement
while relative barriers impose additional costs and delays. Land transportation
networks are notably influenced by the topography, as highways and
railways tend to be impeded by grades higher than 3% and 1% respectively.
Under such circumstances, land transportation tends to be of higher
density in areas of limited topography.
- Hydrology. The properties, distribution and
of water play an important role in the transport industry. Maritime
transport is influenced greatly by the availability of
navigable channels through rivers, lakes and shallow seas. Several
rivers such as the Mississippi, the St. Lawrence, the Rhine, the
Mekong or the Yangtze are important navigable routes into the
heart of continents and historically have been the focus of human
activities that have taken advantage of the transport opportunities.
Port sites are also highly influenced by the physical attributes
of the site where natural features (bays, sand bars, and fjords)
protect port installations. Since it is at these installations that
traffic is transshipped, the location of ports is a dominant element
in the structure of maritime networks. Where barriers exist, such
as narrows, rapids, or land breaks, water transport can only overcome
these obstacles with heavy investments in canals or dredging. Conversely
waterways serve as barriers to land transportation necessitating
the construction of bridges, tunnels and detours.
- Climate. Its major components include temperature,
wind and precipitation with their impacts on transportation modes
and infrastructure ranging from negligible to severe. Freight and
passenger movement can seriously be curtailed by hazardous conditions
such as snow, heavy rainfall, ice or fog. Air transportation is
particularly vulnerable to weather disruptions, such as
during winter when a snow storm can create cascading effects of
air services. Jet streams are also a
major physical component that international air carriers must take
into consideration. For an aircraft, the speed of wind can affect
travel time and costs. Tailwind conditions can reduce scheduled flight time up
an hour for intercontinental
flights. For instance, due to strong jet stream conditions during
winter months, transatlantic flights between the American East
Coast and Europe can gain between 30 to 45 minutes from the
scheduled flight time eastbound. However, for westbound flights
unusually strong jet stream conditions will lengthen flight time
and on occasion force a flight to do an unscheduled refueling stop
in intermediary airports such as Gander (Newfoundland) or Bangor
(Maine). It is expected that climate change will increase the
strength of the North Atlantic jet stream and could lengthen
eastbound flights between North America and Europe. Climate is also having an impact transportation networks
by influencing construction and maintenance costs. Even volcanic
eruptions can have an impact as it was the case in 2010 when an eruption in Iceland released large amounts of
the atmosphere, which forced the closing of most airports in
northwestern Europe as well as the cancellation of many transatlantic flights out of
concern that the ash could damage jet engines.
Many contemporary transportation networks are inherited from the
past, notably transport infrastructures. Even if since the
industrial revolution new technologies have revolutionized transportation in terms of
speed, capacity and efficiency, the spatial structure of many networks
has not much changed. This inertia in the spatial structure of
some transportation networks can be explained by two major factors:
- Costs. The spatial distribution of activities is related
to factors of distance, namely its friction. Locational decisions
are taken in an attempt to minimize costs, often related to transportation.
- Accessibility. All locations have a level of accessibility,
but some are more accessible than others. Thus, because of transportation,
some locations are perceived as more valuable than others.
- Agglomeration. There is a tendency for activities to
agglomerate to take advantage of the value of specific locations.
The more valuable a location, the more likely agglomeration will
take place. The organization of activities is essentially hierarchical,
resulting from the relationships between agglomeration and accessibility
at the local, regional and global levels.
While physical and historical considerations are at play, the introduction
of new transport technology or the addition of new transport infrastructure
may lead to a transformation of existing networks. Recent developments
in transport systems such as container shipping, long range aircrafts and
the extensive application of information technology to transport management
have created a new transport environment and a new spatial structure.
These transport technologies and innovations have intensified global
interactions and modified the relative location of places. In this highly
dynamic context, two processes are taking place at the same time:
- Physical attributes. Natural conditions can be modified
and adapted to suit human uses, but they are a very difficult constraint
to escape, notably for land transportation. It is thus not surprising
to find that most networks follow the easiest (least cost) paths,
which generally follow valleys and plains. Considerations that affected
road construction a few hundred years ago are still in force today,
although they are sometimes easier to circumscribe with civil
- Historical considerations. New infrastructures generally
reinforce historical patterns of exchange, notably at the regional
level. For instance, the current highway network of France has mainly
followed the patterns set by the national roads network built early
in the 20th century. This network was established over the Royal
roads network, itself mainly following roads built by the Romans.
At the urban level, the pattern of streets is often inherited from
an older pattern, which itself may have been influenced by the pre-existing
rural structure (lot pattern and rural roads).
A common fallacy is to relate transportation solely as a force of dispersion, favoring the
spatial diffusion of activities. This is not always the case. In numerous
instances, transportation is a force of concentration and clustering, notably for business
activities. Since transport infrastructures are generally expensive
to build, they are established first to service the most important locations.
For instance, even if it was a strong factor of dispersion, the automobile has also
favored the clustering of several activities in a suburban setting.
4. Space / Time Relationships
One of the most basic relationships supported by transportation involves how
much space can be overcome within a given amount of time. The faster
the mode, the larger is the distance that can be overcome within the
same amount of time. Transportation, notably improvements in transport
systems, changes the relationship between time and space. When this
relationship involves easier, faster and cheaper access between places,
the outcome is a
space / time convergence because the amount of space that can be
overcome for a similar amount of time increases significantly. It is
however a spatially and socially uneven process since it will impact the
accessibility of locations differently. For instance, infrastructure
will not be laid up uniformly and segments of the population will
experience a greater improvement in mobility because of their
socioeconomic status. In spite of these uneven
regional and continental gains were achieved during the 18th and
19th centuries with the establishment of national and continental railway
systems as well as with the growth of maritime shipping, a process which
continued into the 20th century with air and road transport systems.
The outcome has been
significant differences in space / time relationships, mainly between
developed and developing countries, reflecting differences in the efficiency
of transport systems.
At the international level, globalization processes have been supported
by improvements in transport technology. The result of more than 200
years of technological improvements has been a
space / time convergence of global proportions in addition to the
regional and continental processes previously mentioned. This enabled
the extended exploitation of the advantages of the global market, notably
in terms of resources and labor. Significant reductions in transport
and communication costs occurred concomitantly. There is thus a relationship
between space / time convergence and the integration of a region in
global trade. Five major factors are of particular relevance in this
Specialization. From a situation of
diversification, linked geographical entities are able to
specialize in the production of goods for which they have an
advantage, and trading for what they do not produce. As a
result, efficient transportation systems are generally linked
with higher levels of regional specialization. Economic
underlines this process as specialization occurs as long as the
incurred savings in production costs are higher than the incurred
additional transport costs.
Concentration. The continuous evolution of transportation technology may not necessarily
have expected effects on the spatial structure, as two forces are at
play; concentration and dispersion. Linked geographical entities may see the reinforcement
of one at the expense of others, notably through economies of scale.
This outcome often contradicts regional development policies aiming
at providing uniform accessibility levels within a region.
Yet, space / time convergence does not occur in a ubiquitous
manner. In time, some locations gain more accessibility than others
particularly if they experience the accumulation of transport
infrastructures. After centuries of transport developments and their
impacts on geography, global
accessibility reflects a heterogeneous geography. Space / time convergence can also be inverted under
specific circumstances, which means that a process of space / time divergence
takes place. For instance, congestion is increasing in many metropolitan
areas, implying additional delays for activities such as
commuting. Traffic in congested urban areas is moving at the same
speed that it did one hundred years ago on horse carriages.
despite having dramatically contributed to the space / time convergence
is also experiencing growing delays. Flight times are getting longer
between many destinations, mainly because of takeoff, landing and gate
access delays. Airlines are simply posting longer scheduled flight times to factor
in congestion. The termination of the Concorde supersonic jet
service in 2003 can also be considered as a space / time divergence. More stringent
security measures at airports have also imposed additional delays, which
tends to penalize short distance flights. Additionally, direct
transport services can be discontinued and replaced by a hub-and-spoke
structure. The "last mile" can be
the longest in many transport segments. For instance, an express
mail package flown from Washington to Boston in about an hour (excluding
delays at takeoff and landing due to airport congestion) can have an
extra one hour delay as it is carried from Logan Airport to downtown
Boston, a distance of only three kilometers.
- Speed. The most straightforward factor relates to the
increasing speed of many transport modes, a condition that particularly
prevailed in the first half of the 20th century. More recently,
speed has played a less significant role as many modes are not going
much faster. For instance, an automobile has a similar operating
speed in the early 21st century than it had in the mid 20th
century while a commercial jet plane
operates at a similar speed in the 2010s than in the 1970s.
- Economies of scale. Being able to transport larger amounts
of freight and passengers at lower costs has improved considerably
the capacity and efficiency of transport systems. For space -
time convergence this implies that there is more capacity for a
given quantity of passengers or freight being carried. Instead,
the traffic can be handled with fewer trips implying that at the
aggregate level it is moving faster.
- Expansion of transport infrastructures. Transport infrastructures
have expanded considerably to service areas that were not previously
serviced or were insufficiently serviced. A paradox of this feature
is that although the expansion of transport infrastructures may
have enabled distribution systems to expand, it also increased the
average distance over which passengers and freight are being carried.
- Efficiency of transport terminals. Terminals, such as
ports and airports, have shown a growing capacity to handle large
quantities in a timely manner. Thus, even if the speed of many transport
modes has not increased, more efficient transport terminals and
a better management of flows have helped reduce transport time.
- Information technologies (IT). Permitted
several economic activities to bypass spatial constraints in a
very significant manner as IT enables a an improvement of
traffic flows and a better management of transport assets.