In rapid transit terminology, this refers to a railroad track that has been blocked off from any possible intrusions between train stations (i.e. a normal train track deals with crossing roads, doesn't have blocked fencing all along the track to prevent unauthorized entry, and so on). It could also refer to the fact that a guideway has so-called "extra services" on it, such as additional power rails, a magnetic rail, and possible system cable connectors.

In the case of Vancouver's Skytrain, there are always two guideways per station, referred to as the incoming and outgoing guideways. The Skytrain officials use Waterfront Station as the "prime" station, therefore, any trains leaving Waterfront are outgoing, while trains arriving to Waterfront are incoming.