I was done in Salt Lake City earlier this month and I saw some interesting road design that I don't recall seeing anywhere else. At some of the busier intersections they have it set up so that left turning traffic crosses the oncoming lanes up the street from the intersection and they drive down a little "slip road" where they can then turn left. I thought this was really interesting and I can see it potentially being more efficient for traffic flow.
Example:
https://www.google.com/maps/@40.6668...5410&entry=ttu