Traffic monitoring using digital sound field mapping

A new traffic sensing technique is described that utilizes a microphone arr ay to detect the sound waves generated by the road vehicles. The detected s ignals are then digitized and processed by an on-site computer using, a cor relation based algorithm, which extracts key data reflecting the road traff ic conditions, e.g., the speed and density of vehicles on the road, automat ically on site. In comparison with existing traffic sensors, the proposed s ystem offers lower installation and maintenance costs and is less intrusive to the surrounding built environment. The results of theoretical analysis, computer simulation, and preliminary experimental results are presented.