Land Requirement and Consumption

Historically, several environmental aspects impacted the organization and regulation of the footprint taken by transportation activities. Although various forms of pollution were noted since Antiquity, by the 19th century, environmental considerations started to become regulations at the onset of the Industrial Revolution. Zoning restrictions in central business districts forbidding polluting industrial uses were among the first to be implemented. Then, in the 20th-century, land uses judged to be incompatible were separated. The most prevalent were heavy industries and residential areas, which led to a series of zoning definitions of urban areas. Transportation infrastructures, particularly roads, began to have a growing footprint on urban land uses. However, this development is paradoxical since the construction of highways was initially seen as a local benefit, providing mobility and accessibility. It is only later, from the 1970s, that the perspective changed. As providers of mobility, highways were also seen as generators of environmental externalities such as land take, noise, and air pollution.

From the 1950s, urbanization has rapidly seen the expansion of urban land uses, which means that a large city of 5 million inhabitants may stretch over 100 km (including suburbs and satellite cities) and may use an amount of land exceeding 5,000 square km. Such large cities obviously cannot be supported without a vast and complex transport system. Also, modal choice has an important impact on land consumption. The preference for road transportation has led to massive consumption of space with 1.5 to 2.0% of the world’s total land surface devoted to road transportation, mainly for roads rights of way and parking lots. The footprint of transportation has reached a point where 30 to 60% of urban areas are taken by road transportation infrastructure alone. In more extreme cases of road transportation dependency, such as Los Angeles, this figure can reach 70%. Yet, for many developing countries such as China and India, motorization is still in its early stages. For China to have a level of motorization similar to those of Western Europe would imply a fleet of vehicle superior to the current global fleet. From a land requirement perspective, full motorization would generate a massive footprint.

Cities consume large quantities of land, and their growth leads to the notion of metropolitan areas and, further, urban regions oriented along corridors. With urbanization, expansion has allowed the reclamation of vast amounts of land from rural activities towards other uses. Economic globalization and the associated rise in the mobility of passengers and freight have required the expansion of terminal facilities such as ports and airports that have a large footprint. Also, the duplication of infrastructure, public and private alike, have resulted in additional land requirements. This is notably the case for large transport terminals such as ports and airports that were built because they belonged to different administrative jurisdictions. The general aim was to convey a high level of accessibility to answer mobility demands. While in several regions, road transportation infrastructures are overused, a situation of under-capacity exists in others. The formation of compact and accessible cities must be allowed to contend with the already existing built environment while considering several limits to development and urban renewal through temporal constraints and common limitations in capital availability.

The geographical growth of cities has not been proportional to the growth of their population, resulting in lower densities and higher space consumption. This also concerns manufacturing and freight distribution that have the propensity to expand horizontally with the expansion of the transportation and storage functions, particularly for distribution centers. An increase in the quantity of energy consumed and waste generated has been the outcome. Consequently, changes in urban land use and its transport system have expanded the environmental footprint of cities.