The Merits of the Diverging Diamond Interchange - Transportation. What you see above is the "diverging diamond," a freeway-and-surface-street interchange system that reduces the number of conflict points and, in theory, traffic delays, by having drivers switch to the left-hand side of the road temporarily.
It's a French innovation, but it's starting to catch on in the states. This animation, via Core 77, shows how traffic flows through the diverging diamond. So why is it better? The Origin of Words and Names. How to nap.