Shapes are geographical lines. Shapes are used by trips to represent the physical path a bus takes.
There are two different formats for shapes:
GTFS Shape Object
The GTFS definition of a shape. This shape contains an array of shape points. Each shape point has a sequence, a latitude and longitude point, distance traveled, and stopId.
Encoded Polyline
A method of encoding a series of coordinates into a string via a lossy compression algorithm created by Google. An encoded polyline looks like this: