Winter Maintenance Depots 24/7: Winter maintenance in an urban environment

Dominic Guthrie
Acting Superintendent, Technical Operations Transportation Services
Scarborough District Ellesmere Yard, City of Toronto, Ontario
Member, APWA Winter Maintenance Subcommittee

The following article is based on a presentation given at the North American Snow Conference in Peoria, Illinois on May 2, 2006.

Toronto is the fifth-largest city in North America after Mexico City, New York, Los Angeles and Chicago. The city itself has a population of 2.6 million people within its municipal boundaries; however, 5.6 million people live within a contiguous urbanized region referred to as the Greater Toronto Area. The City of Toronto's annual operating budget for 2006 is US$6.4 billion.

Perhaps no other major city in North America performs a similar range of winter maintenance activities at the level of service and on the scale that the City of Toronto does. Toronto's street network consists of 3,600 center lane miles (9,000 lane miles) of roads and 4,500 miles of sidewalks. It receives an average of 52 inches of snow each year, and uses approximately 143,000 tons of salt each winter season. The annual winter maintenance budget is US$50 million. The winter fleet consists of 200 salt trucks, 600 road ploughs and 300 sidewalk ploughs, and 1,600 employees are engaged in winter operations. Logistics is our single biggest challenge.

The City of Toronto utilizes skidsteer loaders to clear bus stops and corner radii following each roadway ploughing operation. The same skidsteer loaders can also be used to assist with any snow removal operations where required.

As the road authority, Toronto's Transportation Services Division was criticized through the 2001/2002 winter season for not salting enough to maintain bare pavement, while at the same time environmental groups and certain Councilors were concerned that we had used over 194,000 tons of salt and were damaging the environment. As a response, we developed a Salt Management Plan (SMP) to improve the handling, storage and application practices for road salt. In Canada, the federal government through its environmental protection agency, Environment Canada, requires that all road authorities that use 550 tons of salt per year develop and implement a SMP and report annually on its progress. The City of Toronto was the first major municipality in Canada to develop a SMP. Our SMP has evolved into a complete winter maintenance plan and serves as a convenient repository for all of our winter maintenance policies and guidelines. Many of the objectives outlined in our SMP, such as good housekeeping practices, regular and proper calibration of salt trucks, the introduction of deicing liquids to our program, the acquisition of pre-wetting and anti-icing equipment, and a greater emphasis on training, were achieved through our Winter Maintenance Depot contracts.

The effective delivery of winter maintenance services in an urban environment presents the road authority with a unique set of challenges. Urban road authorities are faced with having to deliver an ever-expanding range of winter maintenance activities while at the same time meeting the high levels of service laid out for them by elected officials. Further, the residents of large cities are typically more demanding of their public works agencies than those in rural areas. We regularly receive inquiries complaining that we put too much or too little salt on the roads. Often we're asked about why we have to use salt at all or why we don't just use sand; and, typically, we receive calls concerning the damage that salt and our equipment are doing to private property (e.g., grass, concrete, cars).

Over the last two centuries, large North American cities have grown and evolved from centres of commerce to strategic business locations surrounded by expansive urbanized subdivisions. At each stage in the development of a city, infrastructure was constructed to the standards of the day. This has resulted in 21st century urban centers that often have their roots in the 19th century. Consequently, many dense downtown urban areas have little room for snow storage and, as with any developed area where there is a high concentration of people, there exists the possibility for a high degree of environmental impact. With respect to winter maintenance operations, this threat to the environment is manifested through road salt application and the ever-increasing pressures to reduce the amount of road salt used. Toronto is no exception to this phenomenon.

In a busy urban environment, characteristic of Toronto's, there is never a good time to plough snow. Rush hour conditions are often present throughout most of the day. When dealing with different classifications of road, we may be forced to simultaneously salt roads, plough roads, open driveway windrows, plough sidewalks, and clear bus stops. The challenge is in the integration and efficient coordinated staging of these activities across different classes of road. As winter services are rolled out in a staged escalated fashion in response to a winter event, it may take up to 72 hours to fully clean up a typical storm of approximately 4-6 inches. Consequently, an effective internal and external communications plan is critical for the urban road authority.

Toronto chooses to deliver its prime winter maintenance challenges through the use of Winter Maintenance Depots (WMDs). WMDs are winter maintenance yards staffed entirely by contracted personnel who own and operate all of the equipment contained therein. Operators and support staff live in the Depots throughout the winter season. First introduced in 1966, there are now nine WMDs strategically located throughout Toronto. The scope of the WMD contracts include salting, ploughing, driveway windrow clearing, bus stop clearing and snow removal. In the Depot, only the land and the salt storage facility are owned by the City. All other infrastructure is owned by the Depot contractor.

Depots are staffed 24/7 from November 1-April 7 each winter season. All trailers that constitute the administrative and living areas of the Depot are required to be onsite by November 1 each year. Start dates and end dates may be advanced or extended based on forecasted weather conditions through negotiations between the City and the contractor. This flexibility can often provide much-needed insurance against shoulder season snow events. Although the Depots vary in size, there are typically living accommodations for approximately 20 equipment operators and support staff. Included in the Depot are facilities for eating, sleeping, recreation and administration. A typical Depot would contain 15-20 salt spreaders equipped with pre-wetting capability, at least one anti-icing unit, 40-50 ploughs, and 10-15 skidsteers. The City of Toronto currently does not utilize either combination spreader/plough units or ploughs mounted on garbage trucks. All equipment referred to above is dedicated winter maintenance equipment.

The WMDs could be referred to as the keystone within our winter maintenance program, which allows us to maintain a high level of flexibility, especially with respect to response times. All of the salt spreaders for our expressways and arterial roads are housed in the Depots. Approximately two-thirds of winter maintenance services in the City of Toronto are delivered by contractors. We have relatively little equipment compared to the overall size of our winter operation, and consequently we rely heavily on contracted staff.

Although similar, Winter Maintenance Depot contracts are not the same as the Area Maintenance contracts that are utilized by other road authorities. In an Area Maintenance contract, the maintenance area covered under the contract is patrolled by the contractor, and the contractor initiates operations based on levels of service laid out by the road authority. WMD contracts are supervised and inspected by City staff. All equipment mobilizations are also initiated by City staff. The Depot contracts are considered to be no different than summer maintenance contracts, and are correspondingly supervised in the same manner.

Approximately five years ago, Toronto recognized the future potential of deicing liquids and undertook to embrace a fundamental change to the delivery of winter maintenance operations. We retrofitted two existing salt spreaders and converted them to three-in-one-trucks. In addition to the capability to apply dry salt, the units were able to apply both pre-wetted salt and direct liquid application. For two seasons we reviewed the issues associated with a move towards deicing liquids including materials, equipment, application rates and, as always, logistics. From this first pilot project, we have successfully phased in deicing liquids over a three-year period such that approximately 120 trucks are now able to apply deicing liquid solutions. By 2010, we anticipate having approximately 215 trucks equipped for liquid applications. It was determined that the quickest way to make deicing liquids an integral part of our operation was to introduce them through our WMDs. Traditionally awarded for three-year terms, WMD contracts were tendered for a five-year term to allow contractors to amortize this new equipment over a longer period, thereby minimizing the financial impact to the City. Through the Depot contracts we have been able to introduce deicing liquids into our fleet at a faster rate, than had we owned and/or modified the equipment ourselves.

Salt brine was established as our deicing liquid of choice given that it could be produced relatively inexpensively onsite and was most suited to our climate. Responsibility for the manufacture of the salt brine in the WMDs was assigned to the contractor. All equipment in the Depot is paid for both on a daily standby rate for the days that the equipment is required to be in the Depot, as well as an operating rate. The contractor's failure to produce salt brine to the required specification can result in the loss of the daily standby rate for all equipment in the Depot that uses brine. This can be as much as $5,000 per day.

Each WMD contract contains a contingency allowance that enables the City to conduct pilot projects with new technologies. Given the temperature restrictions that accompany the use of salt brine, Toronto's Transportation Services Division has undertaken initiatives to explore the use of alternative deicing liquids that will be effective at temperatures lower than that of salt brine. The objective of these initiatives has been to source out a "one-size-fits-all" liquid that can be used under varying temperature and weather conditions. Due to the number of trucks in each Depot we do not have the ability to choose a specific liquid in response to specific conditions and still maintain our response times. Salt spreaders are required to be full of liquid at all times in order to maintain a continuous state of preparedness.

All road salt used in the Depots is provided by the City. The Depot contractor is responsible for the handling and storage of all salt deliveries to the Depot. Further, the contractor must keep a daily running total of the amount of salt spread, the amount of salt taken by others, and the daily balance in the salt dome storage facility. Any salt spilled by the contractor as part of the delivery operation or usual salt spreading operations must be cleaned up and placed back in the dome. A sweeper is included as part of each Depot contract for this purpose. These good-housekeeping measures are in keeping with the objectives of Toronto's SMP.

The City of Toronto opens residential driveway windrows as part of each roadway ploughing operation. Wings are installed on dedicated driveway ploughs to clear the snow that is deposited at the bottom of residential driveways as a result of roadway ploughing.

Any mobilization of equipment stationed in the WMD is initiated by the city inspector or supervisor assigned to the WMD. Within five minutes of being notified by the inspector, the WMD contractor must load and dispatch salt spreaders from the Depot at the following rates: one triaxle every five minutes; one tandem every three minutes; and one single axle every two minutes. Failure to do so may result in a penalty of up to $100 per minute. The WMD contractor is advised of which salt application rate to use by the inspector who chooses from several predetermined rates. Payment for the spreading of salt is based not on an hourly rate, but rather by the curb mile. In the past, payment for spreading of salt had been based on the amount of salt spread; however, this practice was changed in the current round of contracts to be consistent with the goals of our SMP. All spreaders are equipped with GPS units and electronic controllers for audit and tracking purposes.

The City of Toronto opens residential driveway windrows wherever mechanically possible. Approximately 260,000 driveways are opened 4-6 times each year. The objective of this program is to clear sufficient space for a car to enter or exit the driveway safely. Residents may still have to clear 2-3 inches of snow from the bottom of the driveway. Although this program is our greatest source of complaints when compared to our other winter services, the majority of these complaints are a result of residents' failure to understand the limitations of the program.

As part of every roadway ploughing operation, the City of Toronto clears snow at approximately 10,000 bus stop locations. This operation takes approximately 24 hours to complete. Skidsteer loaders, which are included as part of the WMD contract, are used to clear bus pads, corner radii, open catchbasins and clear sightlines. Inclusion of the skidsteer loaders in the Depot contract also ensures their availability for participation in any snow removal operations when required.

The City of Toronto ploughs snow on all sidewalks where mechanical clearing is possible when snow accumulations reach three inches. Note the proximity of hedges and fences to the sidewalk.

A major component of any urban winter maintenance program is sidewalk clearing. Utilizing 300 sidewalk ploughs, Toronto clears 4,500 miles of sidewalk approximately 16 times per season. It gets initiated when snow accumulation reaches three inches during any given storm and takes approximately 13 hours to complete. The biggest obstacles to the effective delivery of this program are sidewalk encroachments such as retaining walls, raised driveway borders, landscaping features or hedges, and narrow sidewalks which can range in width from 36 inches in the older parts of the city to 60 inches in newer areas. All sidewalks are cleared wherever mechanical clearing is possible regardless of the adjacent property usage.

As indicated previously, the average annual snowfall in Toronto is 52 inches; however, in January 1999, the city received 47 inches of snow in 12 days. This may not seem like a significant amount of snow to road authorities in rural areas or to those who commonly receive heavy snowfall amounts, but Toronto will typically only receive 4-6 storms that will produce 4-6 inches of snow each during an entire winter season. In other words, the snow falls regularly, but not typically in large single events. Such a large amount of snow in an urban area like Toronto, where many busy arterial roads have limited snow storage capacity and where many local roads in older areas rely on residential on-street parking, can seriously impede pedestrian and vehicular traffic for extended periods of time. In response to the storms of 1999, which prompted the removal of 195,000 truckloads of snow from city streets over a three-week period, Toronto developed a comprehensive snow removal plan. The Toronto snow removal fleet consists of 25 snow blowers, 80 front-end loaders, 600 dump trucks, three mobile snowmelters, and two stationary snowmelters.

Rather than hauling snow away to a dump site, the City of Toronto prefers to melt snow onsite whenever possible.

Since 1999, 50% of the dump sites previously available to us have been shut down as a result of growing environmental pressures due to the tendency for them to have been located in sensitive river valleys. As a result, the City of Toronto is in the process of moving towards the onsite melting of snow wherever possible and away from our traditional reliance on snow dumps. Toronto residents have high expectations with respect to the levels of service they receive in all aspects of winter maintenance and, with respect to snow removal, the general consensus is that residents do not like traditional disposal sites located in their neighborhoods because of the appearance in the spring after the snow has melted. These residents' concerns have only hastened our move towards melting.

In summary, the City of Toronto has one of the most comprehensive urban winter maintenance programs in North America, only the highlights of which are presented here. Should you require any further information on Toronto's approach to winter maintenance or the City of Toronto Salt Management Plan, please visit

Dominic Guthrie has been with the City of Toronto since 1989. He was promoted to Supervisor in 1995, responsible for winter maintenance operations, equipment routing, and winter communications. In 2004 he was promoted to Superintendent and is responsible for the City's Salt Management Plan. He is also the secretary of the Ontario Road Salt Management Group. He can be reached at (416) 396-4802 or