Making life easier for people who choose to not own cars, has positive impact for those who can't own cars (and not to even begin on reducing the negative externalities).
For the record, I own a car but also frequently hauled a baby stroller and a diaper bag to the metro train (though only for one kid). The secret was to have a stroller that was geared for walking not the SUV sized strollers so popular with the SUV set.