transit (the company) has some really nice blog posts about the difficulty of making transit maps
https://medium.com/transit-app/transit-maps-apple-vs-google-...
https://medium.com/transit-app/how-we-built-the-worlds-prett...
https://medium.com/transit-app/transit-maps-apple-vs-google-...
https://medium.com/transit-app/how-we-built-the-worlds-prett...
The more general problem Transit seems to be trying to solve (that no one else is) is having a map that can be kept up-to-date with transit alerts and diversions with minimal hassle. For example, it looks like their launch-time picture of Toronto's streetcars (in the first link) was generated when there was trackwork at the College and Bathurst intersection and the corresponding streetcar lines were being diverted around it.
The second link explains rather well the reasons behind some of the problems evident in Google's Toronto map. For example, the unsnapping issue for adjacent lines occurs a lot because streetcar lines are heavily interlined.