SAFETY RESTORATON DURING SNOW REMOVAL By JOHN W. McCREE Illinois Department of Transportation

With the coming of winter, the snow plows will soon be rolling again on our local roads and streets. Clearing snow and ice from the nation's highways costs more than $1 billion annually. Ironically, emergency snow removal procedures can actually compound the problems associated with winter driving by creating additional hazards.

A recently completed Federal Highway Administration study compiled a list of 17 hazards motorists face as a result of snow and ice removal. The most serious hazards resulting from snow removal were found to involve super-elevated and sharp curves; bridge parapets, rails and curbed areas; intersections and interchanges; and actual operation of plows and other snow removal equipment.

The difference in operating speeds between snow removal vehicles and traffic vehicles and the poor visibility created by blowing snow create the potential for serious collisions. Because motorists generally do not understand snow plowing operations, they frequently misjudge the width, length and speed of the snow plowing vehicle. To reduce these risks, amber rotating beacons visible to motorists in front and rear are recommended. The Illinois Department of Transportation has begun testing the use of amber strobe lighting devices as a means of identifying their snow removal vehicles. Lights that indicate plow width increase safety, as do side clearance lights and rear mounted amber signal lamps. An attempt should be made to standardize vehicle lighting systems so that identification of snow plowing equipment is as easy as possible in any kind of weather.

Post-storm hazards often stem from accumulations of ice and snow along roadways and safety features. Snow pushed onto the high side shoulder of super-elevated curves, especially those without reverse shoulder slopes, is likely to melt and refreeze creating sheets or patches of ice on the once-cleared road surface. This condition is especially hazardous because motorists do not expect it or see it. If possible, snow should be plowed to the low side of the roadway or pushed over the high shoulder edge to avoid this hazard. However, care must be taken in piling snow on the low side in the middle of sharp curves as it can reduce visibility around the curve.

Snow windrowed to the sides of bridges and left along parapets, rails and curbed areas is potentially hazardous in two ways. Melting and refreezing on the road surface is likely to occur in areas exposed to the sun. In shaded areas, the snow pushed against parapets, rails and curbs can harden forming icy, extremely slippery ramps of snow. Snow should be removed completely by plowing along the bridge edge, using rubber attachments on the plow blade, if necessary, to protect the bridge features. Creating snow ramps may be unavoidable if the bridge is an overpass, since pushing snow from the bridge down onto another road only transfers the hazard. The ultimate and most costly solution to this problem is to load and haul the snow away.

Snow piled near intersections affects motorists' ability to see oncoming vehicles. This is especially serious at unsignalized intersections. The most effective procedure for avoiding these conditions is pushing or blowing the snow as far from the hazardous area as possible. This avoids expensive loading and hauling.

Other hazards include drains, culverts and channels

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that become clogged with ice and snow. Blocked snow melts into puddles that may refreeze, producing a large sheet of ice on the roadway. Post storm remedies needed to unclog these features include melting the ice with steam or clearing the blockage by hand. Similarly, snow collected along narrow median strips and shoulders obstructs visibility, melts and refreezes into icy patches and renders emergency or shoulder lanes useless.

Road signs obscured by snow and lanes blocked by abandoned vehicles are hazards that can be averted with snow removal procedures or removed with remedies of medium difficulty soon after a storm. Complicated remedies may be required later, however, if vehicles and signs are allowed to become buried in banks of deep snow.

Since snow removal procedures that avoid creating post-storm hazards cannot always be utilized, correct cleanup procedures are critical for preventing these hazards and others. A good snow removal program will provide for post-snowstorm cleanup based on highway features, weather, time of year, hazardous locations previously identified, and route priorities. •

Page 24 / Illinois Municipal Review / October 1988