These detectors measure the changes in traffic system provides data that are useful in relieving the operational problems. This is accomplished by reducing detection time and providing information to the system operator to take timely and necessary traffic management actions. This reduces congestion on the arterial street by reducing delay and fuel consumption. It also increases the operating speed along the arterial street. There is not widely accepted guideline for the selection of sampling detector locations on arterial streets.
Traffic patterns tend to change in relatively short distances on an arterial.
The detector location must be capable of responding to minimize congestion downstream. The pulse mode of detector operation is recommended for sampling detector operation, because it provides greater accuracy. The cost of field data collection and analysis to select the best detector sites is generally greater than the cost of installing loop detectors at all candidate sites and selectively using them as the data reveals the degree of correlation of traffic flows with downstream locations. Correlation of site data with downstream congestion may then be done over time to fine-tune the system.