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Source: adapted from Newman, P. and J. Kenworthy (1999) Sustainability and Cities: Overcoming Automobile Dependence, New York: Island Press. There is an intricate relationship between urban density and energy (fuel) consumption related to transportation. Regional divergences are observed, which are linked with demographic, economic, and societal characteristics. North American cities

The above figure presents two urban spatial structures in terms of form, pattern, and interaction. In the first case, the city is more transit-oriented while in the second, the car dominates. Spatial form. The spatial aspect of a city in terms of its extent. The first case is more centralized

Source: adapted from Google Earth. A modern distribution center consumes a large amount of land, such as the UPS Chicago Area Consolidation Hub (CACH). The 240 acres (97 hectares) site is in co-location with a major intermodal rail terminal owned by BNSF. The distribution center occupies 37 acres (14.9 hectares),

The footprint of transportation jointly concerns passengers (mobility of people) and freight (mobility of cargo): Terminals. Transport terminals consume space for the setting of their respective infrastructures. Their footprint can be extensive, particularly in large gateways where global material flows converge. Networks. Transport routes consisting of networks consume space directly

Each node on a graph has an order with is the number of its links. Graph A is a simple graph with no nodes having an order higher than 2. Graph C is a perfect hub and spoke graph where the hub has an order which is equal to the

Transitivity is the overall probability for the network to have adjacent nodes interconnected, thus revealing the existence of tightly connected communities (or clusters, subgroups, cliques). It is calculated by the ratio between the observed number of closed triplets and the maximum possible number of closed triplets in the graph. Complex

The exponent of the slope for the power-law line drawn in a bi-log plot of node frequency over degree distribution. Networks characterized by strong hierarchical configurations, such as scale-free networks (few large degree nodes and many small degree nodes), often have values over 1 or 2. A value lower than

A measure of connectivity that considers the relationship between the number of observed links and the number of possible links. The value of gamma is between 0 and 1, where a value of 1 indicates a completely connected network and would be extremely unlikely in reality. Gamma is an efficient

A measure of connectivity that evaluates the number of cycles in a graph compared to the maximum number of cycles. The higher the alpha index, the more a network is connected. Trees and simple networks will have a value of 0. A value of 1 indicates a completely connected network.

The Beta Index measures the level of connectivity in a graph and is expressed by the relationship between the number of links (e) over the number of nodes (v). Trees and simple networks have a Beta value of less than one. A connected network with one cycle has a value