A thermochromic self-adhesive film which you place on car headlights - normally clear but close to the freezing point of water changes colour. This would alert drivers and other road users to the possibility of ice being present and allows them to adjust their driving style accordingly.

Furthermore, this thermochromic film could be placed in the 'glare path' areas of the lens so as to take out the colours of light which reflect a lot on interaction with ice and snow - and remove the glare affect commonly associated with driving in icey/snowy conditions.

This film would use thermochromic liquid crystals capable of undergoing their thermochromic transition temperature many times with no noticeable change in performance.
-- Osborn, May 30 2002

I really hate to disagree with waugs but... http://www.crh.noaa.../den/windchill.html
...tell that to the brass monkeys [po, May 30 2002]

Good idea - if wind chill/engine heat doesn't have any adverse effect on this thermochromic film.
-- mcscotland, May 30 2002


thought wind-chill did not apply to cars or at least not in the same degree (sorry no pun intended)
-- po, May 30 2002


Wind chill is an imaginary concept.

What's the advantage of having your headlights change colo(u)r to tell you it's near freezing, as opposed to having a freeze warning light (which many cars have) or thermometer display (which my car has) on the instrument panel that does the same thing?
-- waugsqueke, May 30 2002


For something more tchnical, you could use a set of LED's connected to thermisters.
-- [ sctld ], May 30 2002


Okay, Missblisster.
-- [ sctld ], May 30 2002


I'm not sure your indicator would be very reliable. Whether water on the road freezes or not depends on many factors besides air temperature, such as:
1) Ground/road temperature
2) Rain/sleet/snowfall rate
3) Temperature of the rain/sleet/snow
4) How much traffic there is
5) Whether the road has been salted.
-- beauxeault, May 30 2002


'tis true - wind chill doesn't exist. At least, get the wind moving fast enough and it doesn't.

At {funfactory} we have to take great account of wind heat effect, as the speed of our toys increases.
-- drew, May 30 2002



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