Concise, well-illustrated comparison of transit maps from the developers of Transit for iOS:

Transit maps are hard. Really hard. Even for Apple and Google. Piecing a transit map together, city by city, agency by agency, stop by stop, without it turning into a hairy mess is INCREDIBLY difficult. So far, no one (not even Apple or Google) have been able to create a transit map that is both automatically generated and well designed. Why is that?

As Apple outlined at WWDC, their approach to transit takes a long time because it involves manually curated details (things like signs, directions, and cultural conventions that match the real world), which wouldn’t be possible with an algorithm alone.

That said, I can vouch for Transit in Rome. The app is excellent. Well designed, with some clever interactions (such as an “arrive by” option to plan a trip on a timeline), and a joy to use. It’s also the only decent transit app that combines public transit with local car sharing services on the same map.

I wish Apple Maps transit data was a) available in Rome and b) as flexible as Transit.