>Apropos of nothing... I also remember a story about a northern country replacing traffic lights with LEDs and then spending even more money adding heaters because the old lights were naturally warm, and melted any ice that stuck to the lights. Can't find a link to it at the moment.

The Technology Connections channel on YouTube has an excellent video on this, called 'The LED Traffic Light and the Danger of "But Sometimes!"': https://www.youtube.com/watch?v=GiYO1TObNz8