S.K.
Hi, M.. I think that you got a nasty bus driver, as we all do from time to time. What I get more often are the nasty glare of fellow riders. Even when I do fold my umbrella stroller, it seems to stick out a little, though I make certain never to completely block an aisle. As much as it stung in the beginning and still does from time to time, I have learned to just shake off the stares, the under-the-breath comments, and the rare direct address. In the end, I think I feel sorry for anyone who is that angry with themselves and the world that they cannot have a little empathy for anyone.
I agree with the other moms, that a carrier would probably be a great idea when moving around while the baby is small. Also, I wouldn't hesitate to make complaints (that included employee numbers if noted) to the CTA.
Don't let it stop you from having fun and going out! Enjoy the summer and the closeness you are creating with your baby!