Sonoma Valley motorists registered car-stopping surprise Monday and Tuesday when they encountered a giant construction crane lowering boulders the size and approximate shape of a Toyota Prius on to the raised island inside the circle of the new Arnold Drive roundabout at Agua Caliente Road.
For drivers familiar with roundabouts in other locations, the first surprise was the high, sharp curbs and the elevated mound, encircled by cement blocks with a rock façade, that suddenly occupied the center of the roundabout circle. Conventional roundabouts typically have rounded curbs and low center mass so that drivers can see opposing traffic from across the circle, and so large trucks have room for error in passage through.
But according to Mollyanne Meyn, a Sonoma Valley native and owner of Mira Landscape company who designed the circle feature, this roundabout has a somewhat different purpose.
“The parameters of this roundabout are a little different,” she said on Tuesday, while watching an operator from Summit Crane lower a sofa-sized boulder into the emerging rock scape of the roundabout circle. “The idea here was to obstruct the view,” she explained. “The idea was to slow traffic down. When you see it, it’s quite clear and obvious your car needs to slow down.”
Indeed. The assortment of boulders adorning the circle includes one weighing 22 tons, another weighing 18 tons, and several smaller pieces, each weighing multiple tons. Together, they tower over the road surface by at least 10 feet.