The TravelAction schema is designed markup for to markup your HTML to show the “act of traveling from an fromLocation to a destination by a specified mode of transport, optionally with participants.” But this is not yet supported in search, it is for Gmail markup but not for web search.
John Mueller said on Twitter that it is not supported:

AFAIK we don’t use that in search. cc @danbri
— John ☆.o(≧▽≦)o.☆ (@JohnMu) September 22, 2017
He added later, “as we see more markup being used well, we might start using/showing it.”

Yes, lots and lots of steakholders. “It’s complicated.” :-). Also, as we see more markup being used well, we might start using/showing it.
— John ☆.o(≧▽≦)o.☆ (@JohnMu) September 22, 2017
So use it if you want, where it makes sense, but Google is not doing anything with it right now in web search.
Forum discussion at Twitter.