I'm not a taxi service.

Ok I haven't really been on in a while, but here's my rant for today.

I'm not a taxi service. I got my first car back in September. Neither of my two best friends have a car of their own yet, so that means whenever we want to go somewhere, I'll be in charge of the driving, or at least the form of transportation. However the last few days, I'm starting to think that people think I can just stop everything, and go chauffeur for them!! This is the way the convo went:
Friend: I hate to ask you but can you do something for me?
Me: What?
Friend: Can you take me to *blank*(30 miles away) to pick up my books (for college)
Me: I already went today sorry...
Friend: Well I'd give you gas money if I had it.
Me: *thinking* Well that does me a lot of good doesn't it?
Me: Sorry, I don't think I can do it.
Friend: It's ok.

By the way, her mom does have a car. It's old and isn't in great condition but I really think it would make the trip. And now today, she called again. It's really icy outside too, I actually had an appointment for an oil change that I cancelled because of the weather.

Friend: What are you doing?
Me: Nothing. Did you get your books yesterday?
Friend: No.... could you take me today?
Me: It's really icy today, I don't think I can.
Friend: Well if you could get to my house, I could drive the rest of the way in your car and be careful.... my mom could give you gas money, or I could pay you back in a couple months.
Me: Sorry, it's really icy, and they closed the schools.

Now am I the one being a jerk, or is that really annoying?