• The Council Gritter - more scientific than I knew

I had a conversation about this at lunchtime, so interesting to see this posted up on the BBC website.  I had no idea that's what those discs enbedded in the road and little grey boxes were for:

When snow is forecast, local councils send out the gritters. Trouble spots are identified by networks of sensors embedded in the asphalt. How does this early warning system work?

On roads and highways across the UK, discs are embedded in the road surface to measure climatic conditions. Each is connected by cable or mobile phone technology to an automatic weather station, an unassuming grey box by the roadside.

It's a system developed in the 1970 and 80s and now widely used across the country to track and predict road conditions throughout inclement months. To have accurate information about driving conditions is invaluable to road authorities and local councils to decide when - and where - to send out the gritters.