Is this man attracted to me, and if so, what steps should I take to follow up?

Today I met with a guy at some work training. He was nice and charming and we had a great time talking to each other for about 15 minutes, before the training began. While we were talking, we realised that we were living in the same neighborhood, and he offered me a ride home after the training. I told him that I didn’t know whether or not my boss might want me to work overtime, and thanked him. Then he said he could wait and see whether I would need to work, and insisted on giving me a ride, but I still declined.

He was so polite and I don’t want to fool myself, but I am now regretting not accepting his offer. We’re working in different departments and our firm has more than five hundred employees. I am 3–4 years older than him; he is a trainee and I am senior. This isn’t a big problem for me. He was nice, and I’d like to get to know him better, but I’m really not sure what I should do.