# Are there Reasonably Cheap Sensors Which Could Detect Icy Roads? **URL:** \ **Category:** Factual Questions\ **Created:** [December 18, 2016, 12:12am UTC](https://boards.straightdope.com/t/are-there-reasonably-cheap-sensors-which-could-detect-icy-roads/775003 "2016-12-18T00:12:41Z")\ **Posts on this page:** 1\ **Showing post:** 17
**Author:** ![crowmanyclouds](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/crowmanyclouds/32/19884_2.png) [@crowmanyclouds](https://boards.straightdope.com/u/crowmanyclouds)\ **Post date:** [December 18, 2016, 12:59pm UTC](https://boards.straightdope.com/t/are-there-reasonably-cheap-sensors-which-could-detect-icy-roads/775003/17 "2016-12-18T12:59:54Z")
> [@Hilarity\_N.Suze](#): > > {…} He said…actually, he drawled, “Hasn’t anybody ever told you that an overpass is a lot more likely to have ice on it? On account of the wind currents underneath.” > > Well, I knew that wind chill made it _feel_ colder, but this was the first I’d heard that wind made it actually, factually colder. But obviously I’ve remembered that ever since. > {…} Not “wind chill”, and he’s only sorta right, wind helps the road reach, and stay at, the air temperature faster than on a windless day, > [@Why do bridges freeze before the rest of the road?](https://boards.straightdope.com/t/why-do-bridges-freeze-before-the-rest-of-the-road/96909/2): > > Because the road is protected in part by the Earth below it, and a bridge is chilled by the air passing over it on both the top and the bottom of the surface. > [@Why do bridges freeze before the rest of the road?](https://boards.straightdope.com/t/why-do-bridges-freeze-before-the-rest-of-the-road/96909/5): > > Because the bridge does not benefit from any geothermal heating…in addition to the air circulating above and around it. CMC fnord! --- _[View the full topic](https://boards.straightdope.com/t/are-there-reasonably-cheap-sensors-which-could-detect-icy-roads/775003)._