If you've been in a situation where in vanilla skyrim you go to a carriage, talk to the man, climb on board, then just
wait not going anywhere you may be over encumbered. sigh.
I've had and played the game since release and not once did it occur to me that I wouldn't be able to use them if I had too much stuff. One of those things where I never needed a carriage while I was carrying too much till yesterday. I thought it was a dialogue bug not firing.
Yeah, so facepalm moment and heads up to those who've had that happen.
Sort of reminds me of when I first started the game. Instead of following the main path I took a left and traversed the wilderness. Couldn't find the thieves guild for over 30 levels, I didn't even know carriages were in the game as I never knew to look for them. I remember seeing them, but thought it was 'filler'. Yeah, another facepalm moment. laughs.
-Mush-
What would be nice for more immersion is if the carriage driver would give a sort of "Oh, we can't take you with all that weight you're carrying." Just something to give a bit of a hint besides not doing anything. Who knows, maybe in a mod. (shrugs)