Seamless object tracking at the intersection

In most cities, traffic detection systems have become indispensable.


This article was originally published in Smart Cities World Magazine (March 2021).

Different detection technologies are installed at intersections to manage traffic signals, and to optimize traffic flow. In-ground technologies like inductive loops are replaced by more modern above-ground detection systems. Today, radar, video, or thermal detection solutions are state of the art.
For the attentive road user, such sensors, mounted on mast arms or poles, are nothing new. Normally, one sensor is directed into one arm of an intersection and detects approaching traffic at the stop bar. Forward firing sensors like radar, for example, additionally provide advanced detection capabilities within one single unit. Normally, 4 detectors manage an intersection with adaptive traffic control. However, these sensors work independently and do not exchange any object information among each other.
Although most of the objects including pedestrians and bicycles pass through the inner part of an intersection, this section is of less interest. Imagine there would be a system of detectors providing a full overview of this area as well as precious speed and position data of all objects. The safety and protection of all traffic participants could be significantly enhanced.
Mounting the sensor on the opposite side of each approach results in an overlap of sensor coverage at the inner part of the intersection and this area becomes “visible” to the detection system.

By connecting these 4 detectors to each other the sensors can literally see around the corner. The communication between the sensors not only enables seamless object tracking throughout the entire intersection. It also provides a richer set of data for vehicle-to-infrastructure (V2I or, more generally, V2X) communication.