Through service

This is to be distinguished with operating arrangement which a vehicle changes its service route between revenue journeys at a terminus, but requires passengers to alight or retender fare.

Paris Réseau express régional: In both cases, trains run contiguously, thus providing a one-seat ride across both SNCF and RATP networks.

One example is a Narita-to-Haneda Airport Express service, which runs on four companies' tracks-Keikyu, Toei, Keisei, and Hokuso Railway.

Despite fewer new lines in recent years as the system is mature, more through services are proliferating to reduce cross metropolitan area connection time, at least in theory.

The proliferation of through-services has only magnified the problem, as it acts as a double-edged sword, though convenient in not having to switch trains, central Tokyo delays increasingly cause a ripple effect to through services on suburban lines.

In addition, there are also some through service across different infrastructure owners as well, which include: In the United States, a through train is referred to as interline and is defined as "the interchange of passengers between one or more bus lines, rail transit lines, or railroads" or "the transfer of transit vehicles or trains between routes during a day to improve staff or vehicle assignment efficiency".

For example, morebus routes 16 and 17 may operate as a through service through Bournemouth Square, allowing the passenger to stay on board with a through fare.