If you had seen my lemon yellow 1983 Cadillac you wouldn’t say that.
You also can’t “squeeze into” a bus, ship or train, but you can into a car. It’s a matter of scale.
You can absolutely squeeze into a train or bus … they tend to be quite full sometimes.
Fair point…
Ever tried to get on a bus or the tram/tube/metro at rush hour?!
No, because I live in the US and have no concept of public transportation.
You have Greyhound
Because then it would be carboard

Perhaps it has something to do with trains, buses, and ships being operated/driven by others? You also board an aircraft, a ferry (okay, that’s a ship, but still), hot-air balloons…
Probably because cars are personal and the rest are mass transit. It’s not yours, but you pay to get on board when needed.
I have to explain to non-English speakers why you get in a car or a taxi but get on a bus or train.
It seems to me that the preposition usage corresponds to the boarding language pretty closely. Where “on” sounds most natural is also where “boarding” seems most appropriate.
Here is one linguist’s take, with proposed usage cases at the end: http://itre.cis.upenn.edu/~myl/languagelog/archives/005224.html
The schedule/route condition makes a lot of sense to me. Consider a bus converted to personal use as an rv:
“I boarded my bus and drove to the mountains” is a valid English sentence, but it sounds odd to me. But if it’s still a regular bus and drove->rode it works.
“I drove to the mountains in my bus” sounds better. Same vehicle as a city/school bus, different context. Change to a regular bus and drove->rode doesn’t sound right without also changing “in my” to “on the”.
Interesting approach, but where does that leave taxis?
You board a coach, even if it’s your own coach with them HOERSENS IN FRONTA DEM!!!
You also ride on a bus or on a ship but you ride in a car
Also motorcycles and bicycles.
You can walk on board a bus, boat or train. You sit down into a car.
Witness me!!
You used to need to cross a board or a plank to get on the ship or train but you don’t need that for a car.
You board a taxi, though.
Not with that attitude
You definitely board a taxi though
Not true. When you’re in a car you’re “onboard”.
Evidenced by the “Baby on Board” stickers
You board something you can move around in or on. You get in or on smaller methods of transport.





