freeway bridge drainage. a sound-absorbing wall with holes let

asphalt wall iron roof soil track transport floor vehicle road wood line flooring infrastructure blue walkway lane construction freeway bridge drainage sound-absorbing holes absorbing absorption barriers bellow bent bridge cascade cascading cobblestone concrete cube curved dirt drain drainage flexi flow freeway gray green gutter highway hill hole industrial landscaping lawn long noise wall perforated pipe road roof rough rubber sewage shaft slope slow soil sound splash steep steeple sump tube