Driver description
Interactions within the Social Domain
Interactions with the Economy Domain

Interactions with the Environment Domain
Interactions with the Technology Domain

Impacts on Mobility and Transport

Driver description

  • “Historically, the process of rapid urbanization started first in today’s more developed regions. In 1920, just under 30 per cent of their population was urban and by 1950, more than half of their population was living in urban areas. In 2007, high levels of urbanization, surpassing 80 per cent, characterized Australia, New Zealand and Northern America. Europe, with 72 per cent of its population living in urban areas, was the least urbanized major area in the developed world.” (Ref: CO_1015)
  • “According to United Nations forecasts, by 2050 nearly 70 % of the global population will live in cities, up from around 50 % today. The figure for Europe is higher still: some 83 % of the population – nearly 557 million – are expected to live in cities by 2050. This shift will bring a new set of challenges for city authorities: how to provide the urban population with sufficient water, energy, transport and waste services, and manage infrastructure in a sustainable way.” (Ref: CO_5027)
  • “The growth of urban populations is an important driving force behind urban expansion. However, in Europe, it is not the main factor. More significant is the trend for European cities to become much less compact. Since the mid-1950s, European cities have expanded on average by 78 %, whereas the population has grown by just 33 %.” (Ref: CO_0096)
  • “Recent urban expansion in OECD countries (...) is now largely driven by urban sprawl. Urban sprawl can clearly be seen by the fact that urban land expansion has been faster than population growth.” (Ref: CO_5009)
  • “(...) in Europe today, even where there is little or no population pressure, a variety of factors are still driving sprawl. These are rooted in the desire to realise new lifestyles in suburban environments, outside the inner city.” (Ref: CO_0028)
  • “Urban expansion on a wider front is driven by economic growth and restructuring, new employment opportunities, growth of transport infrastructure, population growth and household change, as well as a decline of traditional rural economies. There are also more intangible factors, such as cultural values, lifestyles, social segregation, and urban/rural attitudes and perceptions.” (Ref: CO_0097)
  • “The models of urban expansion demonstrate clearly the reach of the city in dependence on the technological level of the transportation infrastructure. Given the need to reach the city centre within 30 minutes from home, the first sprawl was possible by the invention of the horse-railway, which allowed an urban perimeter of 10 kms (r=5 kms). The tram extended the radius to seven kilometres. With metro (r=12 kms) and rapid train systems (r=20 kms) after World War II it was possible to allow urban sprawl, orientated to the rail tracks, to an urban perimeter of 40 kms.” (Ref: CO_0036)
  • “Rural–urban migration and the transformation of rural settlements into towns and cities have been important determinants of rapid urban growth but there has also been a general convergence in lifestyles between urban and rural areas as advances in transportation and telecommunication have caused distance and time to collapse. Urban functions are being spread over larger and larger geographic areas so that the traditional distinction between urban and rural areas is becoming increasingly redundant for many purposes.” (Ref: CO_0087)
  • “Urban areas and their hinterland are today not two discrete spaces; they overlap and interlink in a complex system of economic and social interactions.” (Ref: CO_5051)
  • “The residential communities in the periphery are no longer complementary quarters to the core city, but have gained independence and autochthonous qualities, they have become multifunctional living areas. And with emancipation the outskirts gained self-consciousness in an architectural sense as well.” (Ref: CO_0036)
  • “Current urban development – at least in Western Europe - has been characterised also by the shift of business activities to suburbs.” (Ref: CO_0034)
  • “From around 1960 onwards, the European retail sector has experienced an important development at the urban peripheries and in suburban areas. This evolution was basically spurred by the considerable emigration flux towards the outskirts of the agglomerations (suburbanisation of houses and workplaces), the increasing economies of scale in the retail sector, the changes in the shopping behaviour of consumers, problems in city centres (congestion, parking, high ground prices, scarcity of parcels and buildings), the intention of urban planning to improve services in the urban agglomeration and, finally, the internationalisation of the retail sector (with the increasing presence in our cities of hypermarkets Carrefour, IKEA etc.).” (Ref: CO_0034)
  • “Urban sprawl as a dominant trend in post-war European and North American cities is not expected to disappear in the coming years. However, for objective and subjective reasons the increase in urban sprawl may diminish. (Objective reasons include increasing cost of land due to land scarcity; subjective reasons include increasing appreciation of city life).” (Ref: CO_0079)
  • “(...) there is some evidence that urban sprawl has already reached its peak in many cities. Cities are either already experiencing a slowdown of outward migration, or they are expecting one. This means that there is at least the potential for inner-city areas to become more attractive to new target groups (e.g. high-income households, families, older people etc.).” (Ref: CO_0079)
  • “As a main consequence of urbanisation, per capita urban land consumption is increasing, including the land that has been converted from rural to urban use to provide for jobs, recreation and entertainment, shopping, parking, transportation, storage, government services.” (Ref: CO_5048)

Interactions within the Social Domain

Car ownership

Living in urban areas, generally congested and with developed public transport services, allow inhabitants to re-think their mobility behaviour and to abandon the usage of car. Thus it can be expected that urbanisation could be a driver for the reduction of car ownership rates.

  • “The car-free, urban lifestyle is held in the highest regard and offers an alternative to the hegemony of the car.” (Ref: CO_0004)

On the other side, especially in those situations where public transport services are inadequate to satisfy the needs, urban sprawl can be considered as a factor in boosting private mobility and contributing to the increase of car ownership rates.

  • “The EU project SCATTER has listed the widely accepted negative effects of urban sprawl as follows: (...) increase in the use of private cars, traffic congestion (...).” (Ref: CO_5027)


  • “Urban sprawl inhibits the development of public transport and solutions based on the development of mass transportation systems, and the provision of alternative choices in transportation that are essential to ensure the efficient working of urban environments.” (Ref: CO_0028)
  • “Currently we are on a pathway to ever increasing urban sprawl, and in some cases megacities merging with neighbouring cities and towns. These mega-regions, formed by megacities that stretch hundreds of kilometres – sometimes across state borders – form vast belts of high population density and economic power and create huge challenges for governance and mobility. However, this trend is not inevitable and it is possible to reverse it. For example, many urban planners and transport officials today advocate replacing low density car-centric cities and zoned land use with denser, integrated urban villages based around mixed land use, public transport and walkability.” (Ref: CO_5018)
  • “Three aspects, however, receive too little mention or none at all: a) the potential that nonetheless exists in urbanisation – with specific reference here to the setting-up/improvement of effective public and private transport systems – is one of the main tasks facing urban regions in the future. b) Sustainable, resource efficient housing development and the integration of urban and traffic planning continue to be weak aspects of national planning legislation. c) Revitalisation and reurbanisation as an opportunity: as far as residential mobility goes, the potential of towns and cities with regard to their density of service providers represents an important aspect of the ‘back to the city’ trend being observed in parts of Europe.” (Ref: CO_5006)
  • “Mistakes of the past such as urban and suburban sprawl and an automobile-based society should not be repeated. We need a new sustainable design, mass transit, high density, lots of walking for a safe, high quality urban environment.” (Ref: CO_5019)

Change of lifestyle and values

  • “In general, urban populations have a less direct perception of “nature” than rural residents, and typically have higher consumption levels.” (Ref: CO_5048)
  • “A new sustainable mobility freedom concept could take off, especially in the urban environment, with a greater attention of people towards active travel (walking and cycling), combined with the use of high quality public transport and information services, as the main way to ensure freedom of movement.” (Ref: CO_5048)


  • “On the other hand, the urban population may have a greater level of environmental awareness, due to greater access to education and information.” (Ref: CO_5048)


  • “(...) urban sprawl produces many adverse environmental impacts that have direct impacts on the quality of life and human health in cities, such as poor air quality and high noise levels that often exceed the agreed human safety limits.” (Ref: CO_0028)
  • “Slum populations in urban areas are particularly exposed to disease, suffering from poor air quality and heat stress, and with limited access to clean water.” (Ref: CO_2024)
  • “Increasing urbanisation, especially in China and South Asia, as well as ageing of the population (since the elderly are generally more susceptible to air pollution) could be potential contributors to this phenomenon.” (Ref: CO_5009)

Interactions with the Economy Domain


  • “Efficiently operating cities attract investment and jobs.” (Ref: CO_0260)

Availability of public and private resources and investments in the transport sector

  • “In the U.S., road networks as well as public transit systems are subsidized, with revenues from user fees falling well short of the combined operating and capital costs of the systems. Such subsidies, which are common in other countries as well, reduce the cost of travel within cities, potentially encouraging their spatial expansion. This conclusion is not immediate, however, because transport subsidies must be supported by general tax revenue. As a result, while a subsidy reduces the direct cost of using the transport system, it raises the general tax burden, reducing disposable incomes. The first effect causes a city to expand, while the second (by reducing the demand for space) causes it to contract.” (Ref: CO_4015)
  • “From an economic perspective urban sprawl is at the very least a more costly form of urban development due to: increased household spending on commuting from home to work over longer and longer distances; the cost to business of the congestion in sprawled urban areas with inefficient transportation systems; the additional costs of the extension of urban infrastructures including utilities and related services, across the urban region.” (Ref: CO_0028)
  • “Sprawl also increases the length of trips required to collect municipal waste for processing at increasingly distant waste treatment plants and this is expected to continue as household waste grows 3–4 % annually.” (Ref: CO_0028)
  • “The EU project SCATTER has listed the widely accepted negative effects of urban sprawl as follows: (...) higher costs of public services, especially transport (...).” (Ref: CO_5027)
  • “(...) investment in public transport infrastructure is only economically justifiable if housing and employment density is sufficient within the catchment area of the stops. As a result, a consensus is emerging between researchers and urban planners on a density pertinence threshold for public transport of approximately 30 inhabitants/ha.” (Ref: CO_0208)
  • “Transportation investment that acknowledges the unique history, architecture, and ecology of a site can ensure that historic structures, archaeological remains, and wildlife habitats are preserved. (...) This means planners and developers must be careful to avoid damaging or destroying objects of archaeological or historic significance in the path of new transportation facilities.” (Ref: CO_0206)

Intensified competition for scarce resources use

  • “This growing global population also has an increasing taste for resource-intensive goods such as meat and cars. The result is exploding global demand for water and land for crops, livestock, domestic use and biofuels; fossil fuels to power transport or production; and minerals, metals and forests for manufacturing. All of these resources are already heavily exploited, and many face the possibility of severe depletion or even exhaustion in the first half of the century. Scarcity will lead to competition and high, volatile resource prices – it seems likely that the age of cheap oil and cheap energy is over, for example. This will have a knock-on effect on the cost and availability of transport and other goods and services essential to everyday needs in cities.” (Ref: CO_5018)
  • “The consumption of land and soil are of particular concern as they are mostly non-renewable resources. In contrast to changes in agricultural land use, the development of farmland for new housing or roads tends to be permanent and reversible only at very high costs.” (Ref: CO_0028)

Interactions with the Environment Domain

Climate change impacts

  • “Sprawl related growth of urban transport and greenhouse gas emissions have major implications for global warming and climate change, with the expectation of increasingly severe weather events in the coming years and increased incidences of river and coastal flooding.” (Ref: CO_0028)
  • “Cities are themselves sources of global warming: they are “heat islands”, significantly warmer than the surrounding countryside. The main reason for this is the way the land surface is modified by urban development; waste heat from energy use is a secondary cause.” (Ref: CO_0091)

GHG mitigation

  • “The use of energy within a city, and the associated GHG emissions, is dependent on both the form of urban development, i.e. its location and density, and also its design. In this respect, the twin challenges of urban sprawl and the growth of informal urban settlements are especially problematic.” (Ref: CO_0147)
  • “The great challenges of our time are concentrated in the large cities, from where more than half the total worldwide greenhouse gas emissions originate.” (Ref: CO_0284)
  • “Buildings are responsible for more than 40 per cent of energy use in OECD countries and at a global level they account for about 30 per cent of GHG emissions according to UNEP’s Sustainable Building and Construction Initiative.” (Ref: CO_0091)
  • “Buildings can last for decades, even centuries, and it is projected that more than half of existing buildings will still be standing in 2050. As such, the environmental impacts of buildings constructed today will continue for years to come.” (Ref: CO_5009)
  • “There is great potential for cost-effective GHG emission reductions from buildings, with the right incentives and building codes.” (Ref: CO_5009)

Noise levels and emissions standards

  • “Urbanization, growing demand for motorized transport and inefficient urban planning are the main driving forces for environmental noise exposure.” (Ref: CO_0127)

Pollution levels and emissions standards

  • “The level of air pollution exposure in the densely developed centres of cities may often be at higher levels than the suburbs due to the greater concentrations and slower movement of traffic.” (Ref: CO_0028)
  • “Twenty per cent of the EU urban population lives in areas where the EU air quality 24-hour limit value for particulate matter (PM10) was exceeded in 2009 (figure below). For EEA-32 countries the estimate is 39%. EU urban exposure to PM10 levels exceeding the WHO AQG[1] is significantly higher, comprising 80–90 % of the total urban population.” (Ref: CO_0129)

[1] Air Quality Guidelines

  • “Seventeen per cent of the EU urban population lives in areas where the EU ozone target value for protecting human health was exceeded in 2009 (figure below). For EEA-32 countries the estimate is also 17 %.” (Ref: CO_0129)
  • “Twelve per cent of the EU urban population lives in areas where the annual EU limit value and the WHO AQG for NO2 were exceeded in 2009 (figure below). For EEA-32 countries the estimate is also 12 %.” (Ref: CO_0129)
  • “The EU urban population exposed to SO2 levels exceeding the WHO AQG is significantly higher, amounting to 68–85 % of the total urban population (figure below).” (Ref: CO_0129)
Figure 1‑23 Percentage of the urban population in the EU exposed to air pollutant concentrations above the EU and WHO reference levels

Source: Air quality in Europe — 2011 report (Ref: CO_0129)

  • “Traffic-related air pollution is still one of the most pressing problems in urban areas.” (Ref: CO_0229)

Energy availability, production and consumption

  • “There is a general correlation between energy consumption (in gigajoule per inhabitant) and urban density (in inhabitants per hectare). This allows to distinguish several kind of cities, like the American ones, the European ones and the Asian ones.” (Ref: CO_5027)
  • “Evidence shows that there is a significant increase in travel related energy consumption in cities as densities fall.” (Ref: CO_0028)
  • “The diversification of energy sources, fuel types, and vehicles will be greatest in urban environments where the transport and distance requirements are more compatible with diversified energy types and new energy distribution infrastructures.” (Ref: CO_5034)
  • “Electricity use is already growing more quickly relative to other energy carriers as a result of continuous urbanisation” (Ref: CO_1009)

Scarce resources of fossil fuels

  • “The EU project SCATTER has listed the widely accepted negative effects of urban sprawl as follows: (...) increase in fuel consumption and air pollution (...).” (Ref: CO_5027)
  • “Increased average trip length and suburb to suburb trips increase fuel consumption and related emissions of air pollutants and greenhouses gases.” (Ref: CO_5048)

Scarce resources of raw materials

  • “Urban sprawl has also produced increased demands for raw materials typically produced in remote locations and requiring transportation.” (Ref: CO_0028)
  • “Land use change also alters water/land-surface characteristics which, in turn, modify surface and groundwater interactions (discharge/recharge points), to the point that a majority of the small watersheds affected by urban sprawl show hydrological impairment. If the capacity of certain territories to maintain the ecological and human benefits from ground water diminishes, this could lead to conflicts due to competition for the resource.” (Ref: CO_0028)

Interactions with the Technology Domain

Technology development in general and innovation diffusion

  • “Urban centres are the locations of “nodal” interactions that contribute to rapid developments in knowledge, science and technology. Indeed, urban contexts are richer in cognitive dimensions than rural contexts, if only because urban contexts contain more people and a greater range of ideas within a dense setting.” (Ref: CO_5048)
  • “Certainly, ICT-based innovation will be a prominent feature of our lives, particularly in increasingly networked cities, where the ability to be permanently connected could bring better access to goods, services and other people with less need for physical transport.” (Ref: CO_5018)
  • “The peri-urban is also a place of innovation and increasing employment in the service and IT sectors: 25% of peri-urban regions are classified as ‘highly innovative.” (Ref: CO_0097)

Traffic management systems

  • “Cities will be obliged to apply ever-stricter air quality legislation, and to reduce transport-related CO2 emissions in line with increasingly stringent European and global targets. Greater priority will be placed on policies for the prevention and avoidance of congestion, which will inevitably include measures such as access control and road charging to manage the level of demand. Incentives and sanctions will favour low-impact collective and individual modes of passenger transport, while special attention will be paid to goods delivery, with new provisions for truck routing, loading, parking and the associated logistics services.” (Ref: CO_0261)

Information systems

  • “Another mega-trend that is setting the scene for innovation needs in transport is urbanisation.(...) This process will need adjustment and planning, as urban areas increasingly need to manage the demand profile. The key to this are Intelligent Transport Systems (ITS) that provide great possibilities, for example to monitor networks, provide incentives (namely through charges), provide traveller information and enable use of in-vehicle devices.” (Ref: CO_0284)

Pollution abatement and monitoring

  • “Up to now cities that wanted to calculate their GHG emissions either followed their own path or adopted an inventory tool designed for business. ICLEI-Local Governments for Sustainability has now released a draft International Local Government Greenhouse Gas Protocol with two parts: the Emissions Analysis Protocol provides guidance on making an inventory of greenhouse gas emissions and reporting them, and the Measures Analysis Protocol provides guidance on quantifying the emission reduction benefits of mitigation policies and projects. The Protocol goes hand-in-hand with an on-line software tool to plan, monitor and report on GHG emissions and to be released towards the end of 2008 for use by local governments around the globe.” (Ref: CO_0091)
  • “Currently most carbon sequestration initiatives at the urban level relate to tree-planting schemes, and the restoration and preservation of carbon sinks.” (Ref: CO_0147)
  • “In order to study the influence of the different canyon geometries on the street level concentrations, OSPM model results were computed (...) The highest street increments are observed in the narrow canyon case which due to its configuration has the effect of trapping the air pollutants inside the street. This results in high street level concentrations. Assuming the same amount of vehicles per day in the square and wide cases, the PM10 street increments are found to be lower by 33% and 67% compared to the concentrations in the narrow canyon. (...) The model results show that (...) the allowed number of daily PM10 exceedances (35 days per year according to the 2005 limit value defined in Directive 1999/30/EC) is exceeded in almost all cities in the narrow canyon, in 14 cities in the square canyon and in half the cities in the wide canyon case.” (Ref: CO_0229)

Energy efficiency

  • “Along with population size, key activity drivers of energy demand in building are rate of urbanization, number of households, per capita living area, persons per residence, and commercial floor space. As population becomes more urbanized and areas become more electrified, the demand for energy services such are refrigeration, lighting, heating and cooling increases.” (Ref: CO_0105)
  • “Energy intensity trends in residential space conditioning are affected by climate, building thermal integrity, and the heating and cooling equipment.” (Ref: CO_0105)
  • “The greatest energy saving potential lies in buildings. The plan focuses on instruments to trigger the renovation process in public and private buildings and to improve the energy performance of the components and appliances used in them.” (Ref: CO_0198)
  • “[Energy labels] will also soon be in place for buildings EU-wide, with energy efficiency certificates for each property. (Ref: CO_0269)

Impacts on Mobility and Transport

Increased dependence upon private transport due to urban sprawl

  • “Decentralization of cities has been facilitated by the car in combination with efficient public transport. This has resulted in a substantial growth in trip lengths and the development of travel patterns that are dispersed rather than concentrated on the city centre. This in turn increases car dependence and reduces the possibilities of promoting efficient public transport. So transport has acted both as the facilitator of change and as a limiting factor on its resolution.” (Ref: CO_4017)
  • “Urban sprawl reinforces the need to travel and increases dependence upon private motorised transport to do so, leading in turn to increased traffic congestion, energy consumption and polluting emissions. These problems are most acute where residential densities are low and where daily activities (home, work, shopping) are widely separated. There is a sharp increase in car use where land use densities fall below 50-60 people per hectare.” (Ref: CO_0096)
  • “(...) there is an important relationship between the urbanisation driver and daily commuting patterns. Indeed, one of the consequences of urban sprawl is an increasing dependence on the automobile for intra- and inter-metropolitan travel. Urban sprawl entails building extensive transportation systems because houses are increasingly far away from workplaces and commercial centres. This new constructed infrastructure, in return, spurs further urban sprawl – investments made in new motorways or road connections attract new development along the improved transport lines. Growing car ownership and the concentration of work and shopping in out-of-town locations have resulted – and may continue to result - in continuing increases in journey length for all purposes, but particularly for commuting.” (Ref: CO_5048)
  • “The new peripheral retail centres are the result of two tendencies, namely the introduction of new retail techniques - self-service and hard discount – and, secondly, the appearance of shopping centres, combinations of retail businesses and warehouses. If the malls are located away from populated areas, e.g. in rural areas nearby highway connections, it is unlikely that public transport links can be provided at a reasonable cost.” (Ref: CO_0034)
  • “At any rate, if the current trends in the increase of peripheral retail centres continue, a growing transport demand by car is expected.” (Ref: CO_0034)

Congestion in urban areas increases with city size

  • “Congestion in many urban areas has been increasing in its duration and intensity. On average, speeds in cities have been declining by 5% per decade (EFTE 1994) and the severity of congestion increases with city size.” (Ref: CO_4017)

Increasing attitude for public transport, cycling and walking in urban areas

  • “Growing medium-sized urban regions provide a viable passenger base for a functioning public transport system. The challenge lies in complementing the urban structure in a manner that allows the mobility and transport needs of new residents and functions to be efficiently met through public transport.” (Ref: CO_0004)
  • “Public transit and walking transport increase as an area becomes more urbanized.” (Ref: CO_5047)
Figure 1‑24 Urbanisation impact on mode split

Source: The Future Isn’t What It Used To Be. Changing Trends And Their Implications For Transport Planning (Ref: CO_5047)

  • “On shorter journeys, it may be possible to increase the modal share of non-motorised modes, particularly as levels of urbanisation and congestion increase (EC, 2011d). Currently, cycling and walking account for approximately 13 % of urban pkm in Europe, but best-practice examples show this share can be much higher (EC, 2011d).” (Ref: CO_5030)
  • “<In the past 100 years, the automobile has shaped the city rather than cities shaping the automobile. In the future the opposite will be the case: cities will start to shape mobility.> Chris Borroni-Bird, Director of Advanced Technology Vehicle Concepts, GM” (Ref: CO_5018)

Diffusion of integrated services in urban areas

  • “The mobility mixes of urban dwellers differ widely and range from cars to public transport and bicycles. Here, integrated services enjoy a great potential. The Fraunhofer Society highlights first and foremost services located “between” cars and public transport, e.g. car sharing models or demand-driven public transport without fixed routes.” (Ref: CO_0005)
  • “Recognizing that the deeper integration of the urban mobility system is a requirement to achieve greater energy efficiency and provide better accessibility, the roadmap identifies the research needed to enable the integration of the key components of the system, in particular on information, payment and pricing, network management, urban freight, interchanges.” (Ref: CO_5034)