Traffic congesting problems in the roads, especially along the main arterial crossing the city, attract the attention to study the inbound and outbound traffic volumes as well as the traffic volumes along those arterials, especially at key intersections.
Traffic volumes at intersections can be observed and recorded manually or by mechanical hand counters. These machines have been used where pushing buttons manually corresponds to recording vehicles. Recently, and in order to facilitate collection, recording and retrieving of data for short periods of time, electronic data collection recorders have been developed and utilized.
Note : there is a Mechanical one from it named as:
Mechanical Turning Movement – Intersection Vehicle Counter