A novel approach is developed and tested for damping and resolving shockwaves. The approach is based on close cooperation between road side units and equipped vehicles. Road side units detect the shockwave within a few seconds, and then broadcast a dynamic speed limit to reduce inflow and increase the outflow of the shockwave. Vehicles are equipped with either an advisory system or an automatic system to follow the speed profile. Real time detection and control, and adequate response by the equipped vehicles are critical for the success of this approach. The system is developed to work effectively with low penetrations of equipped vehicles. The system has been tested with 68 vehicles on the A270 test site in 2011. First results are presented.