Low heat emission is usually a good feature of LEDs, but it can be an issue in snowy regions.
A recent AFP report noted Japanese police complaining the cool LEDs used in traffic lights were ineffective at melting snow.
Up to 45% of Japan’s traffic lights have replaced incandescent lights with LEDs, but drivers are finding it increasingly difficult to see the frozen traffic signals.
So far snow has been manually removed during December and mid-February blizzards, said Akira Kudo of Aomori Prefectural Police.
"We don't have enough staff members to remove snow as more and more LED lights are being introduced," he said.
This is not the first city to encounter the issue of frost covered LED traffic lights.
Last March Cleveland city in Ohio, U.S. also reported similar issue, and had to resort to melting snow with heating devices.