ABSTRACT
Introduction Transportation modes are ways of moving people and freight. Decisions about which modes to invest in and/or emphasize have long-term consequences. Previous chapters have discussed the importance of the relation of history and cultural factors to modal emphases and some of their consequences for the environment and urban life. Modes may be for passengers, freight or both, and some of their operational and infrastructure considerations are interrelated. All passenger modes have some cargo capacity or potential: personal motor vehicles (PMVs) almost always have some cargo storage; airliners carry much cargo along with baggage in their bellies; most trains accommodate luggage and some carry small amounts of freight; and some ocean freighters accommodate a few passengers. Even walking and bicycling have the potential for carrying some cargo: backpacks and wheeled carts or luggage for pedestrians; panniers and trailers for bicycles, as well as bicycles built as small cargo vehicles. Freight modes and related matters will be discussed in depth in Chapter 5. This chapter focuses on passenger modes and matters related to moving transportation in the direction of greater sustainability. It explores the great variety of modes, differences between modes, and the great diversity that can exist even within a modal category. It emphasizes how modes affect or interact with a number of factors, including:
Two important concepts about modes that should inform our discussion and analysis of them are:
Multi-modal1 : the ability to choose among several modes for a trip. One could travel by foot, bicycle, transit, PMV, or any combination of these. Intermodal2 : the ability to make connections between modes, such as mounting a bicycle on a bus or transferring between bus and rail or between a land mode and a ferry or airport. The convenience of intermodal transfers can be of great value to persons using public modes. Intermodal is also a term that is widely used in freight to denote transfers between trucks and trains, or trucks, trains and ships.
