Five Myths about Salt on our Roads

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The city has been fighting a losing battle to reduce rock salt use since 1977, when they set a target of no more than 2,846 tons each winter. Since then, average annual use has increased by 265%. Missing the goal by so much means we have a complex problem--poorly understood by the public. The myths below persist because the effects of salt are largely invisible.

Unsustainable at CUNA

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Salt storage area at CUNA headquarters in Madison, WI

Runoff is flowing through the spilled salt and into a storm sewer.

Volunteers monitoring road salt impacts on waterways across Wisconsin

By: Kris Stepenuck, DNR Bureau of Watershed Management
Reprinted from "MyDNR Digest" edited by Diane Brinson

The goal: collect high quality data on the impact of road salt on water quality conditions for aquatic organisms, while on a limited budget.

In fall 2010, U.S. Geological Survey (USGS) researcher Steve Corsi approached DNR's and UW-Extension's Water Action Volunteers (WAV) Stream Monitoring Program about developing a monitoring program that would enable volunteers to assist in studying the impacts of road salt on urban streams.

Winter speed limits can reduce the need for salt

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Demand for road salt could be reduced if we found alternate ways to improve winter driving safety.  One obvious way is to reduce winter driving speeds.  Surveys show that the typical driver understands reducing speed improves safety, yet they are unwilling to reduce speed.

Winter speed limits are becoming standard practice on some highways in northern states, and dynamic message signs are a means to achieve this.  The signs flash speed limits, that change in response to weather.

Statistics show that during winter, accident rates do go up.  But not all accidents in winter are due to icy roads.  Many of these accidents would have occurred anyway, without snow on the roads.  So, there's a tendency for the public to believe that all accidents in winter are due to ice.  This creates an unreasonably high demand for salt.

The demand for salt can be managed by opinion surveys, public education, and the promotion of alternate pathways to winter highway safety--such as reduced speed limits and a requirement for snow tires.

A requirement for snow tires can reduce the demand for salt

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There are two things drivers can do to make winter driving safer: Reduce speed, and use snow tires.  Yet the use of snow tires has declined--perhaps because motorists are not aware that modern "all weather" tires are not very effective in snow.

The public demands salt on the road because it makes them feel safer, and provides a better driving experience--meaning they can go faster.  In other words, the typical driver is unwilling to drive more slowly or to use snow tires--and instead asks the government to assume responsibility for safety.

If responsibility for safety can be transferred back to the driver, then there will be less demand for salt from the public.  This transfer can be accomplished through laws requiring snow tires in winter, lower insurance rates for cars with snow tires, and lower speed limits in winter.  Public education is also necessary.

The idea that road salt improves safety--is a myth

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Overuse of road salt is driven by the idea that salt clears the pavement and makes driving safer.  Basically, the public demands bare pavement, and City officials feel they must deliver, or suffer outrage from the public.

"...Perhaps surprisingly, health care and insurance costs arising from winter accidents increase with the use of road salts. Better winter driving conditions encourage increased traffic speeds with the attendant impact that, when faced with severe weather or where road clearing has been compromised by inclement weather, accidents increase on a stretch of highway."  p. 27

"...A study by the Insurance Corporation of British Columbia found that snow and ice-related accidents decreased seven percent (over the 10-year average) in the City of Kamloops following the introduction of new road salts techniques (anti-icing and pre-wetting) while also reducing the City’s snow and ice removal costs." p. 31

Beneath our radar, what's happening is that the Public is transferring responsibility for safe driving to the City.  Once the pavement is mostly clear, drivers resume normal speeds, which aren't really safe in the winter.  Then they blame the City if they have an accident.

What's needed is getting the public to accept responsibility for safety.  This report from Ontario presents a number of ways this can be accomplished--such as requiring snow tires for winter driving, or enforcing lower winter speed limits.

How Ontario is dealing with overuse of salt

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"Here we are, at the frontier of a dilemma that echoes author Rachel Carson’s prescient warnings about pesticides—will our children in their adult years look back and ask, 'Why did the previous generation not heed the warnings about the continued use of these toxic substances?'"