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How to protect pedestrians at an intersection

We have more than one answers to the question we posted on LinkedIn: What should be used to warn drivers to avoid a potentially fatal accident at a pedestrian crossing?

Published June 30, 2021

Pedestrians are the most vulnerable road users and thousands of fatal accidents occur every year. People are particularly vulnerable at intersections, which is the most complex part of the road network – here all means of transport can meet. Pedestrians change their trajectory and speed very easily, so it is worth building protection in the most dangerous intersections that can track their movements very accurately.

In our LinkedIn game a couple of weeks ago, we presented four solutions and asked the question:

How would you warn drivers to avoid a possible accident?

One answer we have suggested is the use of infrared sensors. It’s a bit old-fashioned, but it still works. When a pedestrian passes through the infrared gate, warning lights turn on. Unfortunately the installation requires serious preparation, the road may need to be drilled to accommodate the lights, and the pedestrian may bypass the infrared gate.

Cameras and V2X roadside units (RSUs) are much easier to place on a lamppost. Cameras are already used in many places, specifically for traffic control purposes. Commsignia roadside units are good accessories for them, as RSUs can get information from cameras about pedestrian movement. Recognition works reliably, and it’s harder to avoid.

Closely related to this topic is the possibility of using radio anchors that helps to measure the position of nearby pedestrians. We use ultra-wideband technology, or UWB for short to track people at intersections. Pedestrians only need some kind of an UWB tag, which can be a specific UWB device, maybe a mobile or smartwatch with UWB. The UWB gateway responsible for the positioning, like the cameras, sends data to an RSU, which in turn sends V2X alerts to vehicles in the area.

These developments are particularly exciting because we use sensors and cameras that are also used in cars, only we install them along the roads. With this method, we can increase the safety of all road users, even those who are not equipped with their own sensors.

We’ve successfully tested both camera and UWB based recognition at intersections in the Secredas project, a huge collaboration between 70 European industrial partners to improve road safety and cybersecurity related technologies.

Using location data coming from pedestrians’ mobile phones?

Well, that’s a tough question. Anyone can easily turn off location services manually on a mobile, for example to reduce the power consumption of their device. We can do the same with an internet connection. This must be taken into account when designing road safety systems based on mobile phones.

There are also tasks to be solved on the network side. A much denser installation is needed to be able to tell your pedestrian position extremely accurately – it only depends on 10 centimeters whether someone is on a sidewalk that shouldn’t trigger unnecessary warnings in cars or is already on the road where a warning can save lives.