Greatly Improved Use of Roadside Passive Listening Device

It has been demonstrated by AT&T and others that passive listening devices by the roadside can effectively perform the task of a loopback detector. However, in addition to getting exact counts of vehicles by lane, the acoustic detector can provide additional information such as vehicle speed, vehicle type, and even vehicle maintenance requirements. With a few algorithmic alterations it is possible to significantly lower the cost of these already inexpensive systems. These algorithms allow us to develop a system that uses a PC and a single microphone to accomplish the tasks of a loop-back detector and more.