Thursday, August 4, 2011
Here's an article from Slate that explains how we could make our streets safer and more efficient with increased use of "diverging diamond" highway interchanges. The key insight of the "DDI" is that it eliminates the number of left hand turns that drivers need to make. Left hand turns, it seems, are the bane of traffic engineers:
The left-turning vehicle presents not only the aforementioned safety hazard, but a coagulation in the smooth flow of traffic. It's either a car stopped in an active traffic lane, waiting to turn; or, even worse, it's cars in a dedicated left-turn lane that, when traffic is heavy enough, requires its own "dedicated signal phase . . . ."