Problems with my college roommate

Now my roommate isn't all that terrible when it comes to being clean and other normal roommate stuff. But, she is a terribly rude person. We are in the same major and we have to drive the the barns where some of our classes are (agricultural school). She doesn't have a car and so she asked if she could ride along with me and of course i said yes. Well she has a class right before the one we have together and makes us late every time. Now I feel that why should I have to be late to my class when it's her problem that she doesn't have a ride. We do have free buses that can take her there. Am I just being mean or do i have a point? What could i say to her that wouldn't make her super mad at me? Plus i give her free rides to the barn during our working time there which is twice a day for 2 weeks straight. Also, like normal girls we complain about a few random girls in our major that we both don't care for and whenever we see them out in public she says VERY loudly and sarcastically says "hey look it's your best friend". and in the last instance I asked who and she once again loudly states that the person is standing right behind us in line, who i had just declined a ride to as well since that person never stops talking and drives me up a wall. How do i confront her about that as well? Am I a terrible person for not wanting to give people rides? (There is the free bus)

If you need any clarification please let me know! I would really appreciated the help! Thank you

You should be looking out for yourself here. If you are missing out on class time just because of your roommate, then you need to ask yourself why she dictates you and your car? If she wants to ride along with you, then she needs to realize that she has to comply with your schedule or she can simply take the free bus if that's not good enough for her. Your roommate may be rude but she's also a bully as well. You state you declined a ride to another girl, who talks underwater, but then you turn around and let your roommate disrespect you in front of her. It's not so much about being a terrible person for not wanting to give other people a ride, it's about surrounding yourself with people who respect you and others and people who don't use you to make themselves look bigger at the expense of others.

100% agree!