City employs a host of tools to plan its response to a major storm
For the past two years, Gilles Lavigne has spent his winter months driving a sidewalk plow for Greater Sudbury.
The plows — known as MTs — are those neat little machines you can see clearing walking paths after a storm. When bad weather strikes, the city deploys 20 MTs, fanning them out in five zones across the city with a goal of clearing sidewalks within 24 hours.
Lavigne's rig includes a trailer with sand in the back, so he can sand as he plows. The machines are tricky to manoeuvre, he said, but he tries to avoid plowing snow into driveways. He said he gets frustrated when he has to contend with obstacles on sidewalks that could damage his machine. Newspapers are a common problem, but it's grocery carts that cause him the most headaches.
"I can't tell you how many times, at 5 a.m., I've got to get out and move grocery carts," he said, as he prepared to head out to combat the first major storm of the winter, which hit Greater Sudbury on Dec. 20-21.
Lavigne is part of the front lines of the city's $15-million annual snow removal efforts, which include dozens of plows, trucks, loaders and MTs. When a snowstorm drops eight centimetres of snow, the goal of city crews is to clear roads and sidewalks within 24 hours.
A tall order in a city with 3,600 lane-kilometres of road, but the technology available to staffers gives a huge boost to the efforts.
With big storms, city staff will set up a central command — snow central — usually in the Lionel Lalonde Centre in Azilda. Randy Halverson, the city's manager of operations in the Infrastructure Services department, said the centre allows them to co-ordinate their response.
It starts with a deal with the Weather Network, which delivers detailed information that helps staff plan the when, where and how they will deploy resources.
For example, they know how much snow is expected to fall each hour, and where the concentrations are expected to be heaviest. The information is delivered in three-hour blocks, allowing them to focus resources where they are needed most.
"We track the weather to see how the snow's going to be coming in, and what it's showing here," Halverson said, pointing to information on his computer screen, "is that we're going to start seeing trace amounts of snow around noon."
The detailed weather information allows them to prepare a response plan. For example, if a major storm is imminent, they can initiate a full callout, which mobilizes the city's full fleet of snow-removal machines.
"We use the tools we have to better prepare for the storm," he said. "Rather than wait for it, and then respond, we try to get ahead of the storm."
"Obviously, what we get is a little more detailed information than you would get from theweathernetwork.ca," said David Shelsted, the city's director of roads and transportation.
Greater Sudbury also has access to information from rwis.net, which gives detailed information on road conditions. A puck-shaped sensor in the road on the bridge in Levack give information on road temperature, air temperature, the dew point, and the state of the surface of the road.
"The Weather Network provides us with atmospheric information — what's happening on the radar and our forecast," Halverson said. "This is more about what's happening on the ground level. It captures this information using an infrared camera.
"It's another tool we utilize to help us make better decisions."
Eventually, they would like to add other sensors in sites around the city so they can refine the response even further.
The city also employs automatic vehicle locators that tell them exactly which piece of equipment is servicing which section of road anywhere in the city. Numbered and colour-coded icons move across the screens in real time. At snow central, Halverson said it allows them to monitor snow removal anywhere in the city as it happens.
"They monitor the trucks to make sure they're covering the beats the way they should," he said.
Different types of vehicles get different numbers, so whoever is monitoring the system knows what vehicle is where. For example, 548 is a patrol vehicle; 239 is the sidewalk plows.
"It helps make sure they don't miss a turn or a street or something like that," said Shelsted. "They provide quality control. So in addition to the people we have in the field, driving around and seeing actual conditions, we have someone monitoring the computer screen mapping out where everyone is going."
"This is what out storm centre staff would be monitoring during a storm," Halverson said. "They have copies of our maps showing the beats, so they know exactly what the plow beats look like. They are all structured plow beats."
Halverson said in winter there are five staff on the roads, seven days a week, 24 hours a day, keeping an eye on road conditions and looking for issues.
"If there was a traffic sign knocked down recently, those would be the people who would put in the work order to get that replaced," he said. "During winter weather events, they're on hand to lead the charge with the snow plows.
Rather than wait for it, and then respond, we try to get ahead of the storm.
manager of operations in the Infrastructure Services department
"We have road temperature gauges on the trucks, and air temperature gauges, as well. And that allows them to monitor, say, if black ice conditions were getting close, they could call out the equipment as necessary to deal with those types of conditions."
Each driver is assigned a beat to plow, which, from start to finish, takes 24 hours. Class 1-3 roads are the busiest and are the highest priority for plow drivers, followed by less busy roads classed 4-6. However, once a storm has passed the eight-centimetre threshold required for the city to deploy all its plows, the goal is to have all roads plowed within 24 hours.
"The road classifications are determined by the traffic counts combined with the speed of the road," Halverson said. "Obviously, if it's a higher-traffic, higher-speed road, it's a higher priority. For example, The Kingsway and Barrydowne Road are high traffic roads."
Shelsted said roads plowed early in a storm are often snow-covered again quickly, leading to the misconception that they weren't plowed at all.
"If you have a bigger storm, we'll plow the eight centimetres and do the full route within 24 hours. But by the time the route is complete, another 17 cm has already fallen.
"So oftentimes we get calls, 'You haven't plowed my street.' But we've done one pass in the early or mid-point of the storm, and the snow has continued to fall. We'll come back and start routes over, when that's the case."
"We can never finish our Class 4-6 quick enough," agreed Halverson.
Despite the detailed planning, there are almost always issues, he said. So what happens when a road is missed? Halverson said it's one of a number of factors.
"At times what will happen is we'll get new drivers taking over a beat," he said. "At times, we get drivers helping out in the subdivisions, and they're not entirely familiar with that beat, and at times, they miss a street."
"And sometimes we have drivers who call in sick," Shelsted said. "Right now, everyone's getting the flu. So then you put on different drivers onto the routes."
"When that does happen, the public can call 311 and we have dispatchers, or after hours we have Northern Communications who will dispatch to a foreperson," Halverson added.
The effects of global warming can be seen directly in the winter operations budget, where warmer weather has meant the department is dealing with less snow and thus has come in under budget for the last few years.
Shelsted said the main saving is not having to deal with huge snow banks that used to accumulate in the course of winter. Now there are major rainstorms that reduce the overall snowfall amounts in a year, plus they wash away much of the snow that has already fallen.
But winter rains create a whole new problem for crews: freezing rain and slippery, dangerous conditions.
"If you look at last (Dec. 16), we got up to eight centimetres of snow, and then it changed into freezing rain," Shelsted said. "Last year on Jan. 23, we had a major rainfall event, as well. Historically, we never got those rains in the winter period.
"All of a sudden you have to go from plowing to clearing out catch basins. You have to open them up to allow the water to drain off of the roadways. And then it freezes, so you have to apply material so it's not slippery. And that freezing is the major cause of potholes. So then you're fixing more potholes. And then it snows again.
"The more water you get into the roadway, the more problems we have."
And all the rain washes away the salt and snow they already applied, so crews have to go out again.
"Another problem with freezing rain is that a few minutes after it starts, we have it across the city," Halverson said. That creates an interesting challenge."
And finally, another challenge snow crews face is aggressive drivers who try to pass plows, or who follow too close.
"Our citizens need to drive according to the road conditions," Halverson said.
"And that means slow down when it's snowing, allow a little bit more space between vehicles. Remember: their function is to make the road ahead of them safer. That's why they're out there."
This was the second part of a two-part feature on snow-plowing in Greater Sudbury. The first part is available here.