Transport corridors usually offer a variety of modal options with a linear accumulation of infrastructure. The interactions between these modes usually take three forms:
- Modal competition. When one mode is directly competing with another other or with different firms on the same mode, which is often a zero-sum game. Competition can take place over cost, time, reliability, and niche markets. Each corridor has a passenger and freight balance reflecting their respective competitiveness levels, such as the role of road, rail, and air.
- Modal complementarity. When two or more modes are exploiting their respective advantages. Corridors represent a setting where integrated transport systems through intermodality are particularly suitable to improve freight mobility.
- Modal shift. When one mode develops better advantages over existing modes and captures a share (or the totality) of the transport demand. Although modal shift usually involved a move toward the atomization of passenger and freight flows (diffusion of automobiles and trucks), the current trend in urban corridors involves their massification, particularly through high speed rail transportation.