"jadę" - [to go by a vehicle equipped with wheels, ride; now] (may apply to going by a car, train, bike, rollerblades, etc.) - describes action which is currently in progress
"jeżdżę" - [to go by a vehicle equipped with wheels, ride; regularly, often or always] (may apply to going by a car, train, bike, rollerblades, etc.) - describes habitual activity
I am not convinced wheels are necessary for "jadę"
I can think of some land-bound "vehicles" that do not have wheels and you can "jechać" - sledge, horse, tank, cable way. But
lecieć/latać= fly, go with plane, baloon, spaceship (things that fly)
płynąć /pływać= swim, sail, go with a ship, ferry, boat etc (water transport)
What are some vehicles you cant jechać? And what verb would be used? Non land bound, like a boat or plane?
Well... technically, "travelling" is already quite far from "going", but in this particular example, it seems like a justifiable interpretation. Added.
Why is "I am riding the train" wrong, but "I am riding a train" correct? I've never had a problem with articles before
Very rarely there's any reason for one to be rejected, usually it's just an oversight. Added now.
Is "I take the train" correct? Or jechać is like iść so it's always continuous?