>>43360135Because you're railroaded into the SS Anne.
>The truck cannot be accessed without Surf, which the player would not normally have or be able to use before the S.S. Anne departs. You have to trade Pokémon to do it.
That variety of Japanese truck is extremely specific and rarely driven in Japanese cities.
But, I do have a STUPID and DUMB theory. Wanna hear it?
I think Lt. Surge's gym originally WAS the S.S. Anne. Not in Vermillion City. He was on the ship. This is reflected in the Pocket Monsters gag manga. You can even see evidence in the prototype maps.
So you wanna know whose truck it is? It's Lt. Surge's truck. That's my theory; few urban Japanese drive pickup trucks.
(And it's certainly possible that both areas could have had truck scenery.)