When my Mum was alive, if I was going away, she would always ask which hotel we were going to (in case of emergency), and she would check in on our return date, to make sure we landed safely. As mobile phones came on the scene, I would just text my Mum "Landed".
I have a 25 y/o son, who went off to USA for a holiday recently, travelling alone and meeting up in various locations to meet friends from Uni. I said that he should let someone know his travel plans, just in case something happened, and he accused me of treating him like he's 9. I just thought that was sensible!
His text was quite sarcastic and implied that I have no faith in him as an adult. There is no back story. We usually get along fine etc.
In fairness, I probably think about the "what if's" more than most : my DH is a Police Officer and deals with missing people cases every day. It's amazing how many people don't know where their loved ones are. Can you imagine the conversation?
Parent : My child went on a trip but hasn't returned home
Police : Where did they go?
Parent : USA somewhere
Police : Whereabouts?
Parent : I don't know
Police : Who were they visiting?
Parent : I don't know
Police : What flight were they meant to be on?
Parent : I don't know
Just seems sensible to let someone know your plans. I didn't even say it had to me, it could be his Dad of GF, just someone!
When me and DH go on holiday, I always text the kids and tell them where we are going and when.
Maybe it's just my family history? DH's family never ask when he is due back from holiday, and in all honesty we could have been kidnapped abroad and it would be 6 months before his Dad would even notice we were missing.