Is she interested or is she just being polite?

I believe that she is interested in you she may not be touching you cause she doesn't do that to guys that she likes and she maybe doesn't want a ride home cause she doesn't want her family to know about you cause they will tease her. I wouldn't be to worried I reckon she likes you, you should ask one of her friends to ask her or get a mate to ask. hope I helped :)

If she's shy then chances are she'd never touch you or anything. If likes you, she'd by shy to talk to you first. She doesn't want to make you think that she likes you.

But based on the good signs, I'm pretty sure she likes you. Talk to her more and show her signs that you like her so she would be more comfortable in expressing what she truly feels inside.