The best option is to remove yourself from that situation completely. Not only is it rude to gossip, there is a thin line that you cross where it becomes a breach of confidentiality. If you say something about little Sue's test score and one of the other teachers talks about that at the local coffee shop where Sue's aunt overhears, you all could be sued, fired, and lose your certificate.

Keep it positive. If you are around negativity, you become negative. I would find a new ride personally.

I would keep quiet and try to change the conversation. I'm pretty assertive, so I would probably say something in regards to not talking about work.

In order to keep myself out of trouble I would try to change the subject if they continued I would find myself another ride and inform an administrator. I would not want to get myself into any situations where I could get in trouble.