I just sent an IM in English:
This is just a short message, as I'm outside now at a fireworks festival in Nagaoka city in the Niigata prefecture. I could wrap up today's work at 15:30, so we decided to hop onto an express train to Niigata and just a few hours later made it to one of the most famous fireworks festivals in Japan. I wish you could've joined us, but it just so happens that it is broadcast live on YouTube, so go ahead and enjoy it. ;)
In English, the verb "hop X / hop on X / hop onto X" comes in handy to express the idea of suddenly deciding to get on some public transport on a whim. The focus here is on the unplanned nature of the train/ferry/plane trip. I was wondering how I would idiomatically say this in French.
Given that the fundamental meaning of "hop" is "jump", I'm half tempted to use "sauter". Then again, when I say "sauter sur/d' un train", I rather associate it with the reckless manner in which you jump onto/out of a moving train:
Qu'est-ce qui t'a pris de sauter sur un train en marche ?
How do French speakers commonly express this idea?