What is meant by alignment?
Alignment refers to the vertical or horizontal placement of the tracks. Vertical alignment refers to track placement relative to grade (or ground): at grade, above grade (on a viaduct or berm), or below grade (in a trench or tunnel). Horizontal alignment refers to geographic placement: for example, through the Pacheco pass and up the peninsula from San Jose or over the Altamont pass, the Dumbarton Bridge and up the peninsula from Redwood City.
