A couple of weeks ago, I had a brush with death. Well, not really, but it felt that way for a few seconds.
I was in Asheville, NC at the intersection of Airport Road and I-26, a “diverging diamond interchange.” This video shows you exactly how traffic flow works, where one is essentially crisscrossing and driving on the left side of the road for a bit. It gave me that feeling of inching out to pass a slow car on a two-lane country road. Maybe I had not read the signs correctly? I was just waiting to have a car or truck plow into my SUV. I held my breath, prayed and white knuckled it.
While it may feel wrong at first, diverging diamond intersections have a purpose. The idea is to improve traffic flow by eliminating risky left turns across traffic. This relieves congestion, improves safety and, because these bridges are already in place, saves money and ROW.
France has been using this traffic strategy since the 1970s. It’s taken a little longer for diverging diamonds to make their way stateside, probably because of feelings like those I expressed above. But the strategy is catching on, and I’m told here are now about 75 of them in existence in the US. Gratefully, I’ve overcome my initial resistance and appreciate the flow they provide in highly congested areas.
Maybe these will become a standard option for interchanges, just like the roundabouts we first “discovered” several decades ago. The efficiencies provided, especially when making left turns onto the interstate, are something we can all get used to.
