encyclopedia

ABSOLUTE PERMISSIVE BLOCK

A block within which the movement of trains on a desigated section of track or tracks is directed by signals automatically controlled and without train-order authority and without superiority of trains.

ABSTRACT CHOICE MODEL

A model based on the assumption that it is not necessary to identify travel choice variables by the name of their mode, destination, time of day, or other characteristic; instead, they are identified by their attributes, for example, variables describing…