Scientists create ‘smart’ road signs that use radar to warn drivers about hazards ahead
A team of leading researchers have developed ‘intelligent’ road signs which can warn drivers about hazardous road conditions ahead.
The smart road signs use several forms of radar as well as a range of weather and traffic sensors to collect information and a built-in algorithm to process data as well as Bluetooth to communicate with one another.
The signs also use a unique built-in radar system combined with wireless technologies and sensors, to collect information on weather conditions, traffic and hazards on the road to warn drivers in real-time.
The innovation includes a 'Doppler radar' based on the Doppler effect discovered by Austrian physicist Christian Doppler in the 19th century.
The Doppler Effect, which refers to the change in wave frequency during the relative motion between a wave source and its observer, helps to explain why an ambulance siren sounds higher pitched when approaching us and lower pitched after it has passed us.
The specialised Doppler radar will be built-in to the traffic signs and transmit pulses of radio waves directed at vehicles and other moving objects on the road and measure the difference between the transmitted impulse and an echo in order to measure their velocity.
It is already used in police speed guns and along some roads to take speed readings and tell drivers to slow down if they are exceeding the limit, but the smart signs will also use it to measure rain drops hitting the road's surface.
The use of Doppler radar will be complemented by the use of acoustic vector sensors (AVS), technology more commonly used underwater, which works by reading the motion and pressure changes of reflected sound waves.
It would be used in the road signs to calculate traffic on a section of the motorway by showing the direction in which a sound wave is travelling and how many other sources of sound are nearby.
The information will be used to alert drivers to any congestion in front of them. AVS can also be used to analyse sound signals to provide a better picture of road conditions in both wet and dry weather.
Lead project scientist from the Gdańsk University of Technology, Professor Andrzej Czyżewski, said: “We can calibrate an acoustic vector sensor [AVS] so it can be used to measure highway traffic volume and count vehicles by analysing the noise they emit as they go by.
“Although the acoustical vector sensor – the embodiment of acoustic radar – has lower accuracy than Doppler radar at vehicle counting and isn't able to measure vehicle speed with the same precision, it has key advantages over Doppler sensors.”
Another innovative aspect of the system is the way in which road signs would communicate with each other and with motorists over a special form of Bluetooth WiFi system called vehicle to everything (V2X) technology designed for fast moving objects and compatible with Bluetooth enabled cars and smartphones.
Czyżewski said that the technology would “actively react to the traffic situation, suggesting to drivers the speed appropriate to the situation.”
The smart road signs were due to be rolled out earlier this year, but were delayed by the pandemic. When introduced, it is hoped they will help to prevent major road collisions.
The system is being pioneered as part of a national Polish project called INZNAK, financed by the Polish National Centre for Research and Development, Poland's Public agency for scientific innovation.