When they say that Bologna is closed in August they are not kidding, so you may want to go on some excursions. Other tripadvisor members who have recommended day-trips from Bologna seem to have had cars. For those of you using the cheap and reliable trains I would recommend that you aim to arrive after 5pm when visiting Parma or Ferrara. Between midday and 5pm (the hours you would normally visit somewhere on a day trip) they are ghost-towns. Better still, go to Florence (open all day!) or spend a bit longer on the train and visit Venice.