Northern light wrote:No, snow does not vaporize when using salt, it changes the melting point and snow/ice becomes water. What point that water freezes again depends on the mixture.
It snows. The city spreads salt. The snow melts and becomes water. You now have wet roads instead of snow-covered roads.
It stops snowing.
Cars/trucks drive on the road, which flings the water up into the air as a mist. The air turbulence from wind and the traffic itself causes a small portion of that atomized water to drift away from the road, and over onto the shoulder. That is, less than 100% of it falls back onto the road. After a period of several hours, the road is dry.Sand:
It snows. The city spreads sand. The snow turns brown.
Cars/trucks drive on the road, which packs the snow down into a dense, brown mass. The wind doesn't matter, because the snow isn't going anywhere. After a period of several hours, the road is still covered in dirty snow.If
the weather turns sunny later, and
it's not too cold, then the sun warms the snow (because darker colors absorb light), it melts, and finally begins being flung airborne by traffic and may drift off the roadway, as in the salt case. But if it's nighttime, or overcast, the road simply stays covered in snow.
Northern light, I'm not arguing hypotheticals here. I've driven in both, extensively. I know what I'm talking about. This is how it works.
Northern light wrote:So, yes- salt it is an effective way to clear roads fast when it is not very cold.
As I said before, salt is effective down to -20 C.
Northern light wrote:As stated, it is also an effective way to ruin cars through corrosion.
That's one drawback, yes. My '05 car is showing growing rust on the rear quarter panels. Of course, it's got 280,000 km on it, so it's only got a couple more years in it anyway. But you're right, in "salt" jurisdictions, rust is usually the limiting factor to vehicle lifespans.
Northern light wrote:I figure that is a bit more expensive than repaving the road every 8 years instead of 10 because people use studded tires...
Huh??? What are you talking about? Why in the world would the municipality care about rust on your car? They're not the ones paying for your car! They do
, however, pay for the roads, so can you really not see why their priority would be to preserve the lifespan of the roads (which they pay for) rather than the vehicles on the roads (which they don't
Northern light wrote:Again, if people use winter tires, 1-2 inches of snow on the road is not a big problem.
Agreed. But studded tires don't make enough of a difference to warrant the massive damage they do to roads. And salt is far, far more effective at making roads driveable than sand.