IT'S ice time across much of the Northern Hemisphere. And in many places, the roads, once again, are white with salt as well as snow.
It makes driving safer while our cars rust, bridges corrode, and the environment absorbs more of an undesirable chemical. This raises the perennial question: Isn't there a more benign alternative to this corrosive, polluting de-icer?
A study committee of the US National Academy of Sciences' Transportation Research Board doesn't think there is an affordable alternative. It has just released a report of a cost/benefit comparison between salt and salt's leading challenger, calcium magnesium acetate (CMA). It notes that CMA costs over 20 times more than salt. It also finds that, while CMA is much less corrosive and environmentally damaging than salt, the chemical is less effective at lower temperatures and in freezing rain, drier snowsto rms, and light traffic.
"Rock salt remains the heavyweight champion in the fight against icy winter roads," the academy says in announcing the study. However, one should take that statement, itself, with at least one grain of salt. CMA may not be the alternative of choice. But the committee's cost analysis justifies a major research effort to find a way to greatly cut down on road salt.
The United States alone uses about 9 million metric tons of road salt. That accounts for about $500 million of the $1.5 billion yearly highway ice and snow control bill. The cost of undesirable side effects is even higher - probably very much higher.
When it includes that expense, the committee puts the total cost of salting at over $2 billion. That's conservative. The committee says it couldn't get a handle on costs of environmental damage and water pollution. These costs could be monumental if salting damages reservoir supplies and underground aquifers to a substantial extent.
Winter driving safety is important. Highway authorities will have to continue salting until they have a cost-effective alternative. But the cost of salt damage may be far higher than realized.
The federal government should underwrite a nationwide research program to pin down that cost and to find alternatives to the annual highway "seasoning."