Spotted at the airport:

haveanicejourney
In Chinese:

祝大家旅途愉快

祝 zhù wish

大家 dàjiā everyone

旅途 lǚtú journey/trip

愉快 yúkuài happy/cheerful

Or, in English, 🙂 Have a nice journey (or trip)!

It’s also easily adapted wishing, say, you friend or family to have a nice trip! Just switch out the 大家 for or

大家旅途愉快

=

旅途愉快

  • (nǐ) you

旅途愉快

  •  (nǐmen) you (plural)
  • Remember, of course,  (men) us used to make subjects, referring to people, plural!