The silence from the annual SR-520 bridge closure this weekend reminded me that it’s been one year since different types of quiet pavement were installed as a test on the stretch near where we live. A graph on the WSDOT site shows the results of decibel measurements each month since last summer’s paving. The rubberized asphalt and polymer-modified asphalt have met up at the 100 decibel mark, still beating out the new control pavement. But it’s a five year test so these numbers don’t mean much yet.