I think proposal C is an excellent way to implement that.. ie:
existing route_types (probably with the addition of proposal A) and a
route_subtype that maps to a more specific type. (i'm saying that the
0,1,2... in subtype would not necessarily always mean the same thing)
I think i'd rather see C over B even though they are not quite
mutually exclusive, they are quite related.
as for uses, i like the current granular ability of route_types
because i use route_types 1 and 2 currently, and so i parse those out
of feeds. (yes i would be able to do the same for a longer list if
they were 3 digit fields)
I think the parking_available idea is worth exploring, but i don't
like that 0 means both undefined/default and no-parking available..
ie: there is a zero in the feed. is it unknown if there is parking, or
is there no parking? (there are also probably other similar types of
fields like wheelchair_accessible, bike_parking, ...). There is also
the question of how this relates to stops and the parent_station
field.
--
Jehiah