Through service

A through service is a concept of passenger transport that involves a vehicle travelling between lines, networks or operators on a regularly specified schedule, on which the passenger can remain on board without alighting. It may be in form of either the following:

• A service where the vehicle travels between different lines, or systems of infrastructure, for example, a through train service between the mainline and underground railways.
• A service where the vehicle changes its identity en-route without requiring passengers to alight, for example, a through tram service which runs as route 1 initially, then runs as route 2 for the latter half of the journey.

The term through service may be extended to have a wider meaning encompassing a route which allows the passenger to travel without alighting, for example, in a route change announcement, if a route A-B and a route B-C is combined to A-B-C, it may be described as a new "through service" between A and C.^[1][2] This is in contrast with direct service, where a through service may be a circuitous route but allows the passenger on board for the whole circuitous journey. 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.