Arlington has spent quite a lot of money on traffic calming in many of its neighborhoods. Traffic calming is meant to slow traffic to the stated speed limit or make cutting through a neighborhood as time consuming as taking the packed main route. It uses narrowed entryways, speed humps and obstructions in the roadway—oops, that’s traffic circles—to accomplish this. Neighborhoods have to agree to the changes, which has resulted in bad feelings and controversy at times.
I don’t have anything against traffic calming in principle. But I have some observations about the speed humps and the traffic circles. The first is that in many neighborhoods the speed humps require almost a full stop before driving over them. They should be designed so that if you drive over them at slightly below the speed limit, your car will be okay—no scraping bumpers or undercarriages. There’s probably a reason why this is not the case; perhaps to discourage anything but local traffic.
My second observation is more serious. The traffic circles are often too big for the street, thereby becoming obstructions in the roadway. In the neighborhood near me where they have been installed, they caused several accidents initially. I also think they endanger pedestrians because they take up enough roadway that a large vehicle (by which I mean an SUV, not a garbage truck) actually moves into the crosswalk in many cases as it negotiates the “circle.” Also, people don’t always treat them like circles, which would dictate bearing right if you want to exit left. Below is a picture of the mother of all traffic circles. Note how close it is to the crosswalk on the right.
I’ve seen people turn left behind the circle in front of an oncoming car that’s just trying to go straight. I’m wondering if there are statistics on traffic accidents on streets in Arlington where traffic calming elements have been installed. It might be interesting to see what they show.