by David Murphy
It can be helpful. For example, if your car's thermometer reads 32 degrees, you're definitely getting an indication of possible ice on the roads. But there are other things to keep in mind. For starters, the thermometer may not be accurate. I become extra cautious as soon as I get readings in the 35 to 36 degree range. This not only allows for thermometer error, it also takes into account the fact that the air temperature may be milder than the ground temperature (the only temperature that matters, when it comes to possible ice beneath your tires, after all). Also, remember that certain road surfaces freeze sooner (often before your thermometer hits 32). Examples include bridges and low-lying gullies. You should always use extra caution in these locations.