The traffic detection system includes an optical unit having an emitter module emitting pulses; a receiver module having a field of view including a plurality of adjacent detection channels receiving pulses reflected by an object and acquiring and converting the received pulses into a corresponding plurality of a digital signal waveforms; an image sensing module providing an image. The method comprises providing a status overlay image including the image and a visual indication on the image of an outline of the plurality of adjacent detection channels; positioning the field of view to cover the detection zone using the status overlay image; obtaining the plurality of digital signal waveforms; detecting a signal echo caused by an object in one of the digital signal waveforms at a position within the field of view; determining a location for the object using the position; storing the location for the object.