Either that, or Zoey has fear of flying
But yeah, traveling by train is quite normal here in europe, even for distances of about 500-600 kilometers. Also I know Americans loveto drive by car/land (during my trip there I had no problem driving from Las Vegas to LA and I've heard it's quite normal for people to do there), but from Hamilton to San Diego is a completely different story
Smoking weed currently doesn't affect anything other than dialogue with some girls/on some routes (like Jill and Zoey), the ability to have sex on the roof with Quinn (mandatory for her path) and the ability to use mushrooms on neutral affinity in episode 10.