[Mazrim]

Originally Posted by Fuzz

Just like this:

https://goo.gl/maps/XqmU9aD9XhTioujC8

We should also be doing a lot more of this:

https://goo.gl/maps/e5j1nKF198W9YEJS7

and a lot less of this:

https://goo.gl/maps/XMSTVGbtD2ffyXXu7

Our obsession with putting endless numbers of traffic lights on interchanges is baffling, and really bad for the environment.

If you look at your second link and move around that highway, all the higher volume interchanges have traffic signals on the roundabouts. A roundabout can only handle so much volume before it fails and signals need to be installed, so it's worth keeping that in mind when saying a roundabout is a one-size fits all solution.

Free flowing interchanges are very expensive to build, and if you're worried about the environment, you should consider the embodied carbon cost of excessive concrete and steel bridges and asphalt and concrete lane kilometers constructed when it comes to free flowing interchanges versus more compact intersections using signals. Most signalized cross roads at interchanges perform quite well since the biggest volumes (the main road the cross road no longer interacts with) are removed from the equation.