Seconded on their usefulness on the road. Incredibly easy to just reach over, hold the PTT button and get your message across. One time purchase for something that won’t get shut down or unsupported ever.

If you try communicating with a phone, the only safe way to do it (assuming one person per vehicle) is to start a phone call before leaving, and keep it running constantly. If you have a passenger, they become your secretary. If the call drops then that’s all comms lost until both pull over and redial. Requires mobile coverage everywhere on your route which in Australia isn’t the case, even on major routes like A1 Bruce Highway.

Walkie talkies are king for travelling with mates

Obviously that would be a total compromise. However this all depends on your threat model and how you usually use your laptop, and if someone were to steal it, would they also mug you for your flashdrive?

In my case, I just type the passphrase I have into the laptop, although my homelab server uses a USB so that it can unattended reboot, and I can put the USB in a secure location if it doesn’t need to reboot unattended.

Otherwise, in my case I usually go out with a laptop that if stolen, is only worth about $150 AUD so not a big financial hit. While I have LUKS as a passphrase, I’m not likely to be a target of any individual or entity that, if they really wanted my data, would also mug me for a USB key, so I could live with either.

It’s quite possible to set up LUKS with a USB key instead.