Smarter traffic signs (IMAGE) Acoustical Society of America Caption Researchers in Poland have created smart road signs that use built-in Doppler radar, video, and acoustic radar and weather stations to monitor road traffic and conditions to warn drivers in real-time of hazards and prevent collisions on highways. Credit Czyzewski Usage Restrictions Journalists may use this image only with appropriate credit. License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.