"I am 1k and there is one thing that annoys me to no end - that is United doesn't put a much bigger sign on each of the middle overhead compartment to let people know their luggage will not fit unless turned horizontally for 99% of the luggage carryons.

Every flight I take, there are multiple people that insist it will fit and end up costing an entire line jam, and a few times my own luggage that's completely positioned correctly to be slammed against closure that I have to yell at people to stop shoving their luggage in.

I feel like this is something that can be prevented if they show a video before boarding (while people wait) or a gigantic sign to let people know it will not fit. Sigh."