Has there ever been a study about how many lives a year road salt saves?
I’ve suggested this needs a forum change to Comments on Cecil’s Columns.
I doubt that that data exists outside of fairly speculative statistical inference for drivers.
Conditions differ greatly across the country, and some places use magnesium chloride in place of sodium chloride and they both have very different properties and effective temp ranges.
Sodium chloride, which would be road salt only really works in areas where temperatures stick around close to freezing as it rapidly loses effectiveness as the temperature drops. At 30F 1lb of salt melts 46 pounds of ice, but at 10F it only melts 5 pounds. In Minneapolis they had to resort to potassium acetate on some of the bridges due to this issue.
With those caveats called out, this study claims around an 88% reduction but their dataset is pretty small, so I would take their numbers with a grain of salt. 
http://www.trc.marquette.edu/publications/IceControl/ice-control-1992.pdf
Indeed. Done.
samclem, moderator.
I was born and raised in snow country, and there isn’t any doubt in my mind that it is literally a life saver.
Agreed. Living in snowy and icy winters the only question becomes whether there are environmentally safer alternatives than sodium chloride, not whether road treatment is necessary. Plows don’t leave bare dry pavement, so the highway plows I see are invariably dump trucks with salt spreaders at the back. Besides melting residual snow and ice, salting is also necessary to deal with conditions that create treacherous black ice, a rare but dangerous condition where a road looks normal and clear but is actually covered with a thin super-slick layer of ice that provides almost zero traction. For all these reasons, roads have to be treated. The environmental effects are unfortunate and so is the effect on car bodies, but any alternative would have to be cost-effective in large volumes.
Ignored in the article and almost ignored in the comments is the impact - through acid-induced rust - on car bodies.
I suspect that the cost to the community (not strictly to the environment, admittedly) is massive. Think of the energy required to mine the ore, refine it, press body panels, etc
I keep my cars six years. I’ve owned a Saturn, a Cavalier, and an Elantra, and I’ve never seen a speck of rust on any of them. Of course, I wash my car (with under carriage wash) frequently in the winter every time the weather gets above freezing, so I’m sure that is a factor.
Road salt is intrinsically a corrosive substance and bad for car bodies. That cars last much longer than they used to is due to better engineering both in the bodies and the drive train, with lots of anti-rust components especially around the underbody and wheel wells. These days you would expect a six-year-old car that had been reasonably cared for to look and function almost like brand new, but salt is still a contributing factor to rust and general deterioration.
I own a 16 year old Cavillac (Cavalier) and it only has one rust spot on a quarterpanel, which I will be fixing when it gets warmer. Regular car washes work wonders getting rid of salt.
Most larger departments of transportation are trying to substantially reduce the amount salt they apply: see for example Minnesota’s approach:
There’s something about bulldozing a 60 foot wide strip through the middle of paradise … dumping 24 inches of crushed gravel … laying down 4 inches of asphalt … running carbon-polluting cars back and forth … people throwing garbage out the windows … building hotels, rest stops, signage, overpasses, culverts, fences, utility poles, and what not …
Yeah … an occasional sprinkling of salt is BAD for the environment …
I’ve got a 15 year old car, 250k miles, that has spent it’s entire existence in snowy climates. Yes, salt does still cause some rust on modern cars, but other wear and tear will kill my car long before the salt does.
In Mount Bachelor, the road salt was replaced with sand for the environmental reasons described (mostly concern for the deciduous trees).
I suspect that it does not work as well. While you’ll always see cars sliding on icy roads, there were a lot more per mile than I had seen in other mountainous areas.
I can’t link to the story from my phone but Lake Simcoe, in Ontario, had a salt concentration of 10 micrograms per litre in the 1970s. The concentration is now 50 micrograms per litre. And Lake Simcoe us pretty decent sized. While I don’t doubt that salt makes roads safer it does come with a cost.
Possibly this:
It may not be what you were looking at but it contains the same information.
I think part of the reason is that southern Lake Simcoe is within a rapidly growing population area. It’s just beyond the northern part of the Greater Toronto Area, close to the city of Barrie and the towns just outside the GTA that are experiencing population booms. I don’t know what the hydrology of the area looks like, though, but no doubt there is considerable drainage into the lake.
I see a lot of efforts to reduce salt usage. Not necessarily practical and effective efforts, but at least they’re trying.
Yep. Despite being in New Hampshire and Maine for its whole “life,” the 2007 I just traded in had one spot of rust on it the size of a quarter. This is a massive improvement over the car I had before it that was just six years older.
I live in the Midwest and the frame of my previous car (a 2000 Ford Focus) basically rotted away.
Thirded. Minnesota simply would not be driveable in the winter without some kind of ice melter. Plows can scrap off snow but ice gets bonded to the pavement and cannot be cleared mechanically.