trips are the bus routes we care about

routes are basically useless other than color

calendar is what service_id refers to

need to figure out how to turn shapes into polyline

routes <-> stops daisychain is as follows

trips.txt: route_id -> trip_id

stop_times.txt -> trip_id -> stop_id

to get shape info it's

trips.txt: route_id -> shape_id

shapes.txt: shape_id -> shape_pt_lat+shape_pt_lon+shape_pt_sequence
