I'm sorry to hear that

Better off without him! My health got better after she left. Lost over 50 lbs really 50 + 270 she left!

Really hatin' that for you.
He did it via text because he is a fucking coward and couldn't bring himself
to do it to your face.
It hurts like hell, and sucks for now, but it WILL get better.
You're going to be okay. I really believe that, or I wouldn't have said it.
Try to enjoy the rest of your trip. You're starting a new chapter.
What better way than with a road trip with someone you love?
Safe travels!!!

First, I'm very sorry to hear that. That is such a huge event. He exhibited extremely bad form (and cowardice, as has already been mentioned) in texting you. And doing so while you were off vacationing with your son seems downright hurtful. His behavior says volumes about how much he has ever valued your relationship if he didn't even have the guts to end things in-person; very little. Again, very sorry to hear this. You have tons of moral support in this community. Use it. =]

Total cowardice. Find a lawyer with taxidermied testicles on her desk.

Text breakups are bad enough, but ending a marriage that way is unforgivable.

Wow, that is low. I bet this is a guy who specialized in avoiding conflict, right? My sympathy goes out to you. Bad enough to get the boot, worse to not hear it to your face. Good luck, sounds like he's doing you a favor even though it might not seem like it right now.

Because he's a coward.

It’s a dick move.

What a coward

Probably a cheater and definitely a pathetic excuse for a human being. The signs were there long before the text. Don't beat yourself up...he's the asshole here.

Do you normally have good communication with him? Like is this a sudden view of a completely hidden idea, or have you suspected that he was unhappy?

On the surface knowing only what is posted I would naturally agree... I also suspect some things may have been left out of the story. I would need more information and actual facts about your relationship and how things have been lately if I were going to take sides. Apply critical thinking to more than just religion... you seem nice, I wish you well... I would not do that... but you have a 9 year history and have posted a 5 line singular event.

A coward ex wife did it in a letter as she snuck out of the house. Then called 2 days latter wanting to come back. I had time to look through the dedts she left. Still think she took alot of money hidding it.

Right now you are in a world of pain anguish and confusion, once this fog has cleared you will see, he wasnt for you..or any other self respecting woman or parent. Whatever happened between you, he has declared to you and now indirectly to the world that he is a useless, week, crude little man with no class whatsoever, you can't see this now, but what a fortunate woman you are to have found this out, albeit in such a cruel and pathetic fashion.

I'm very sorry that happened to you.
We are here for you.

That's so uncool...

From the very little that we know, he either just doesn't care, or he's a coward.

I am so sorry. This is a very cruel thing he did. I hope you have been able to salvage your time with your son. Your husband is not kind. I agree with others here; why would he do it this way, because he knows how wrong it is for him to time this with the first day of your annual mother son road trip and he is so ashamed of himself he can not even face himself, let alone you. in short he is a cowardly man. 

As several other people have said: He's a coward.
I'm so sorry you have to go through it.

Fear of a scene. My soon-to-be ex-wife left me a note and the divorce papers. A text is even worse. I’m sorry he did it that way. It’s really shitty.

Because they're too afraid of a row.

Wow! I have no words.

Maybe it was the only way to get the message to you?

He's made a decision , he is not going to allow you any say in the matter , he's gone .