Considering that a growing share of the global population lives in cities, urban transportation issues are of foremost importance to support the mobility of passengers in large urban agglomerations. Transportation in urban areas is highly complex because of the modes involved, the multitude of origins and destinations, and the amount and variety of traffic. Traditionally, the focus of urban transportation has been on passengers as cities were viewed as locations of utmost human interactions with intricate traffic patterns linked to commuting, commercial transactions, and leisure/cultural activities. However, cities are also locations of production, consumption, and distribution, which are activities linked to freight mobility. Conceptually, the urban transport system is intricately linked with urban form and spatial structure. Urban transit is an important dimension of mobility, notably in high-density areas.