Table w/ 2 columns feat. the same foreign key (accessing?)

I have a database table named trips which has two columns (in addition
to others) which both have foreign keys to the locations table. The
columns are for a start location and an end location. The problem arises
in the trip model in trying to access each location.

belongs_to :location, :foreign_key => ‘start_location_id’ gives me
access to one of the locations but how can I access the other?

Thanks