Google wont throw an error on this sort of problem.
The method I used was to go to maps.google.gom and past your address in to the search field:
804 Texas St, Fairfield, CA 94533
Google displayed the map, but asked me if I meant to use:
804 N Texas St, Fairfield, CA 94533
804 W Texas St, Fairfield, CA 94533
When calculating the directions, if the same address exists in two location like N Texas St, or W Texas St, google will get confused if you dont tell it which one to use.