Credit goes to u/Stelith61 on r/CitiesSkylines for posting this:
I can't wait to try recreating and experimenting with different designs!
http://www.cbrd.co.uk/interchanges/
A bunch of interchanges with explanations of the pros, cons, and a simple diagram on their construction. All driving on the proper side of the road.
It also has a page for the worst interchanges in Britain. (http://www.cbrd.co.uk/badjunctions/) and other stuff I'm too simple to understand.
I can't wait to try recreating and experimenting with different designs!