Using detectors

You can use detectors to record vehicles or pedestrians for vehicle-actuated signal controls.

A detector must be assigned to the desired signal controller and can be limited to the PT lines of your choice (Attributes of detectors).

To record traffic volumes in your Vissim network, use data collection points and evaluate them with data collection measurements (Defining data collection points), (Evaluating data collection measurements).

Using detectors to record vehicles

In order to record vehicles for traffic-actuated signal control, various types of detectors are deployed, such as induction loops, infra-red sensors, pedestrian push buttons, overhead wire contacts, point-blocking circuits or reporting points for radiotelegrams.

In Vissim you model detectors of a specific length as network objects on links (Defining detectors). A message impulse is then transmitted to the signal controller as soon as the front of a forward driving vehicle reaches the detector. Another impulse is transmitted as soon as the tail of the vehicle leaves the detector. These message impulses are interpreted by signal control logic and converted into appropriate switching signals for control. The detector does not detect vehicles that are reversing. The detector detects platooning vehicles as individual vehicles.

Using detectors to record pedestrians

Vissim recognizes pedestrians on pedestrian links by means of detectors. If a pedestrian leaves a pedestrian link or enters a free pedestrian link, Vissim detects this at the end of a signal controller time step. The change from occupied to vacant or vacant to occupied are transmitted to the control logic as the front ends and rear ends. If you have selected a sound file, it is started when the first pedestrian arrives at an empty detector.