A salt-sand combo

The Glengarry News - Glengarry Supplement - - News -

While we never know what Win­ter will throw at us, provin­cial, mu­nic­i­pal and county road main­te­nance crews know in ad­vance how to re­spond to storms.

There are some ba­sic strate­gies, as out­lined by the On­tario Min­istry of Transportation.

Spread­ing of salt be­gins within 30 min­utes after the start of a win­ter storm, help­ing to melt snow and ice, pre­vent­ing it from stick­ing to the high­way. It also makes plow­ing more ef­fec­tive.

Sand is used to pro­vide trac­tion on slip­pery sur­faces, es­pe­cially when it is too cold for salt to be ef­fec­tive. It may be used at higher tem­per­a­tures if trac­tion is needed im­me­di­ately, par­tic­u­larly on hills, curves, bridges and in­ter­sec­tions, and on snow-packed high­ways.

Both are spread on the high­way us­ing a truck that car­ries the ma­te­rial in a hop­per. On two-lane high­ways salt is di­rected through a chute and gen­er­ally placed in a nar­row strip along the cen­tre of the high­way. On multi-lane high­ways, spin­ners are used to spread salt across one or more lanes at a time.

Salt is less ef­fec­tive at tem­per­a­tures be­low -12° C, es­pe­cially if there is no sun­light, which means bare pave­ment can be dif­fi­cult to achieve in ex­tremely low tem­per­a­tures.

There's no “one size fits all” re­sponse to win­ter storms. The win­ter main­te­nance equip­ment and ma­te­ri­als used de­pends on weather con­di­tions (tem­per­a­ture, pre­cip­i­ta­tion type, du­ra­tion and in­ten­sity, cloudi­ness, hu­mid­ity, wind), high­way con­di­tions and amount of traf­fic. That's why main­te­nance crews con­tin­u­ally mon­i­tor weather and high­way con­di­tions. They pa­trol the high­ways and use ad­vanced sys­tems for pre­dict­ing and mon­i­tor­ing weather and high­way con­di­tions so they can pre­pare the right equip­ment and ma­te­ri­als be­fore a storm, ad­just their ac­tiv­i­ties as con­di­tions change.

Anti-ic­ing

Anti-ic­ing liq­uid can be sprayed on a high­way be­fore a storm to pre­vent snow and ice from form­ing and stick­ing to the high­way. It can be placed along a sec­tion of high­way or at spe­cific lo­ca­tions prone to ic­ing, such as bridge decks. Anti-ic­ing liq­uid is only ap­plied at spe­cific tem­per­a­tures and weather con­di­tions.

Equip­ment

Once the storm hits, snow plows, com­bi­na­tion trucks and tow-plows are used to clear the snow and re­store the high­way to bare pave­ment con­di­tions. A stan­dard snow plow truck has a blade mounted on the front and may also have a side blade or “wing.” A com­bi­na­tion truck has a spreader mounted on a stan­dard snow plow truck and is ca­pa­ble of both plow­ing and spread­ing. A tow­plow is a reg­u­lar plow blade mounted on a trailer and pulled by a com­bi­na­tion truck. The trailer is moved over to the right to clear the next lane.

On­tario 511 is an On­tario Min­istry of Transportation tele­phone ser­vice that pro­vides the pub­lic with voice-ac­ti­vated, hands-free in­for­ma­tion on provin­cial high­ways. Just dial 511.

A QUES­TION OF DE­GREES: Road salt be­comes less ef­fec­tive be­low -12 de­grees; sand is used be­low -18 de­grees to im­prove trac­tion.

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