[Daves911L]

There is what I think is a derivative of this "double diamond" intersection (didn't know what it was called until now) a few miles west of me. Its not over a freeway, but at what was the intersection of two very busy 4-lane highways. It opened about a year ago, replacing a light-controlled intersection with left turn lanes. It took forever to build, and i assume was very expensive. It is very weird, and requires a very large chuck of real estate. It is confusing. There is a lot of striping and signage, but a bit like the back straight at sebring, just so much flat concrete you are not really sure which way is ahead. 1 long and irritating light was replaced by 3 shorter lights. It seems quicker going through now, but that may be perception more than reality, from breaking up the wait into 3 intervals. The opportunity for head-ons is real and on two occasions I have personally seen cars going the wrong way down the counter-intuitive "changeover" lanes.

I'm finding myself entertaining the notion that this and other bizarre traffic engineering I've seen in the past decade are actually intended to discourage private vehicle use, in favor of mass transit.

There are several local examples of the "traffic circle fetish" here. Where some community activist or local politician set about to get a traffic circle built just because it was the "cool" thing to do. Don't get me wrong, I think traffic circles work great. Negotiated them easily while driving in Europe for decades. But there is a right way, and a wrong way, to build them. They require good visibility both on approach and when in the circle, and an adequate radius. Many of our local traffic circles are built the "wrong" way and do more harm than good.