The Christos Crossroads (aka Criss-Cross Roads design)

This my own design. I sent it to Main Roads WA but they did not like the fact that you can also exit a highway on the right, but I think people will get use to exiting on the right, with clear signage, and you can also use LED flashing lights above or on the road to get people into the correct lane.

By using bridges it is possible to have a free flowing traffic intersection of two main roads.
The handdrawn diagram shows you how it works. The right lane must turn right and the left lane must turn left. Where they peel off is a matter of choice. The diagram is repesentative only and the traffic on the lower road (that is not using the larger overhead bridge) can tunnel underneath the oncoming traffic to turn right instead of going over the top.
 
Below is a rough sketch of my design.



After coming up with this continuous flowing traffic intersection, I have become aware of the clover-leaf design (see below) which I think is fabulous, but I think mine can be made with less land uptake. The problem with the clover-leaf design is that it requires a much bigger land area to implement as the 270 degree turn for drivers who want to turn right pushes out the road for cars which are turning left in that quarter. In any case, I do not know why Main Roads does not use the clover-leaf design much at all, but come up with all sorts of half baked hanky-panky bridge and traffic light designs.



The Christos crossroads design requires much less land area but requires more support either in bridges or retaining walls if tunnels are used.
 
The concept can also be used at busy T-junctions to allow continuous flow of traffic. I have a diagram somewhere but you can probably work it out for yourselves.