Temperature sensitive paint
Many deaths each year are caused cars slipping on ice. A lot of the problem is that it is hard to know when there is ice on the roads, so drivers can't take this into account in how they drive.
Engineers at a company called Eurovia may have come up with something that will help - Temperature sensitive varnish. The idea is to paint this varnish onto the white paint on the road, and above 1 degree celcius the varnish is completely clear. But the varnish contains a thermochromic pigment which turns pink below 1C so drivers are warned of the low road temperature where there may be ice. When the temperature increases to above 2C the pigment will go clear again.
They have got the varnish to survive the battering it will receive on the road, but they are still working on making it visible enough at night and they may have problems with UV damaging the dye in the summer, but this marks a great step forward in using innovative solutions to make our roads safer!