* At a glance, some sort of automated progress tracker would be my first request. I'm certain that I'll end up missing sections and/or losing my place and drifting away as long as it's manual.
* Offering an estimate time to completion is great. Leveraging those estimates to give me an option to select 'something that will fit in 5/15/60 minutes' from my current topics would be even better.
* The site snaps, that's great.
* Creating a TOC of the off-site content (video, books) in the overview of each roadmap would be nice. If I decide that I'm going to commit to follow one of these roads I'm going to be looking to source the books and download the videos so that I can watch them on the subway.
* Interactive 'exercises' where possible. This is a major plus of the EdX courses I've done - submitting results or complete Python code and getting instant feedback.
* Suggested background / prerequisites for a roadmap would be nice as well.