Nav System example

You don't enter an origin. The NAV system calculates from your current position, and recalculates in real time.

To enter a destination, press the DEST button on the side of the MFD. The destination screen comes up, from which you can select how to enter the destination. You can pick from saved destinations, previous destinations, an address, an intersection, from the map, or by entering GPS coordinates. If you have an existing destination selected, you are given the option of replacing that destination or adding the new destination to the route. After that is settled, if you select "guide" the system will offer three different routes: quick1, quick2, or shortest. You select one of these and guidance begins.

Tom

 

See http://priuschat.com/forums/prius-main-forum/48495-how-use-prius-navigation-system.html

 

See also:

Toyota Navigation System

 

Just to add to Tom's clear and detailed answer, if you would like to determine a route from a specific "origin", simply enter that origin as your first destination (effectively as a waypoint), and your true destination as your second destination.

The routing, distance and instructions between destination 1 & 2 will be what you are looking for...