Boarding Tracks are rails that, unlike Powered Tracks, stop and hold a minecart while unpowered, preventing it from being pushed off. Thus allowing players to climb into an unoccupied Minecart, or stop a Tank Cart to be filled, for example.
Boarding Tracks also have an arrow on it that points in the direction that the cart will be propelled when the track is powered. This makes for a preferred alternative to Powered Rails for the purposes of Minecart launchers in passenger rail systems.
There are two versions of Boarding Track: one intended for use with individual carts, and one designed to work on entire trains. Visually, the two are identical, so care must be taken to craft the proper track suited for the player's purposes.