Thin noise reducing pavements - Experiences

Like porous pavements, thin layer pavements have a noise reducing potential on urban roads as well as on high-ways. In Denmark a project on urban roads was started in 2003.The goal was to develop and test thin layers as noise reducing pavements under Nordic conditions.This project is a part of the European SILVIA project started in September 2002.Another Danish project with test sections of thin layer pavements on a highway was started in the summer of 2004.Thirteen test sections have been constructed on urban roads and five on the highway. Dif-ferent pavement types are included: 1. Open graded asphalt concrete. 2. Stone Mastics Asphalt. 3. A thin layer constructed as a combination pavement.Dense asphalt concrete pavements with maximum 8 or 11 mm aggregate size are included as reference pavements.Comprehensive measurement programs have started. Noise is measured by the SPB method.The pavements will be described together with the results of the first series of noise meas-urements.In 2004, a new research project on optimization of thin layers started as a co-operation between the Danish Road Institute/Road Directorate (DRI) and the Road and Hydraulic Engineering Institute in the Nether-lands (DWW) called the DRI-DWW noise abatement program.This new project is focusing on optimising the noise reduction and to find the long-term noise reducing effects of thin layers.The project plan for this new pro-ject will also be presented.