I have been at my workplace for 5 years, and a few months one of my colleagues moved house, to my area.
I drive to work each day, and when we were having a chat about her moving, she mentioned the idea of car sharing to work, with her contributing towards the petrol costs. I thought this sounded ok.
At first this worked fine, she gave me petrol money and it was quite nice having the company. But for the past month or so, she’s not given any petrol money, I’ve mentioned it a couple of times and she’s given rubbish excuses about how money is short at the moment. (Which makes no sense, as if I didn’t drive her, she would have to pay for public transport!) She also mentioned that she is saving for a holiday so the financial hardship claim doesn’t really add up 
Another thing which is really getting under my skin is that she’s completely stopped saying thank you. When we get to her house and she gets out, she just says goodbye. I know this might seem petty, but I find it incredibly rude.
I get the impression she feels entitled to a lift since we live close by.
AIBU to stop giving her lifts entirely? I feel like I’m being taken advantage of. I am on annual leave until Monday so I want to cut off this arrangement before I’m back at work.