Plowing snow: despite the science, hardworking people still needed to move the white stuff

Mike Schmidt got his first taste of snowplowing on Oct. 31, 1991 – the infamous Halloween Blizzard that saw 28.4 inches of snowfall over a four-day period. So, you will forgive him if the 15 inches that fell recently was something of an annoyance by comparison.

That was 30 years ago, and now Schmidt has been working for the Eden Prairie streets division for 26 years.

On a day in between storms, he shows off the interior of one of the 20 massive dump truck plows in Eden Prairie’s fleet. The dashboard looks like a passenger jet cockpit. The plow outside his windshield is massive.

All of it to move snow. Efficiently, quickly, and safely.

In Eden Prairie, that task belongs to Schmidt and the other 43 drivers who operate those trucks and 19 pickup trucks with plows that clean snow from 230 miles of streets (580 in-lane miles – some are two lanes wide) and 630 cul-de-sacs.

But snow removal has also become a technological wonder thanks to global positioning systems (GPS) and cell phones, compared to the old days that relied solely on citizen band radios (CBs for those of you under 50) for communication, sensors that measure the ambient temperature of street surfaces, and a system that tracks the movements of all of those vehicles in real-time.

Tracking with precision

The 15+-inch snowstorm that lasted more than two days earlier in January tests the department’s systems and personnel.

It’s Scott Riley’s job to make sure it all works smoothly. As the manager of Eden Prairie’s Streets Maintenance Division, he and his crew are responsible for cleaning the city’s streets after a snowfall.

During a storm, Riley sets up shop in the department’s command center, which doubles as his office.

A large-screen television is mounted on one end of the office, and Riley monitors Precise, an automatic vehicle location (AVL) system, from his desk.

Every snow plow is equipped with an AVL, which uses GPS to track vehicles as they move through the city.

In his command center, Riley can see it all playing out in front of him. Not only can he see where all of the trucks are located, but with a single click on the circle that shows its location, Riley can see the vehicle’s speed and the rate at which the plow is dispersing a salt and brine mixture on the street. Some trucks also report the ambient, or average, temperature in their location.

Having all of that information at his fingertips allows Riley to move trucks to other locations where they are needed. He can also check on complaints he receives from residents about how fast a truck was going, or that a truck isn’t treating a street with salt.

Weather information system

While trucks are able to relay important information to Riley, the city also has installed non-intrusive pole-mounted Road and Weather Information Systems (RWIS), infrared cameras pointed at the street that gather important data.

“At any time of the day or night, we can look at that system and determine if it’s rain, if it’s snow, is it sleet, ice, what’s the road temperature?,” according to Public Works Director Robert Ellis said. “What’s the ambient temperature, the street temperature, what’s the relative humidity? [It’s] all the information that we need to know how bad an event might be, or how big or little of a response we need.”

The weather information system can also be set up to send an alert text message or an email to Ellis, Riley and others if it senses moisture on the road.

There are actually two different information systems, and the city is planning to add a third, Ellis said.

“We’ve got two of them because different parts of town where at times we’ll get a bunch of snow down south along the Minnesota River Valley,” he said. “We might not have anything going up at Crosstown.” 

Not too heavy on the salt

The RWIS and AVL systems also provide information that helps Riley and plow drivers determine how much salt to drop on the streets.

“Eden Prairie uses less salt on streets than many nearby communities,” Riley said. “Our standard is about 100 pounds per street mile. Many cities are dumping 300 pounds or more because they aren’t monitoring how much is actually needed.”

Dump trucks are loaded with regular salt, mixed with a 23.3% salt and water brine mixture from containers attached to the rear of the trucks. That mixture works well until temperatures get down to about 10 degrees F. That’s the same mixture used to pretreat major streets ahead of a storm unless rain is expected, Ellis said.

When it gets colder, trucks are loaded with a premixed product containing magnesium-laced salt that works down to about 10 below zero.

Drivers then set the rate digitally in their trucks to 100 pounds. “Then we’re only throwing 100 pounds of salt, which is very, very low,” Riley said. “ I mean, we are very, very conscious here.”

“We don’t want to use any more salt than we have to,” Ellis added. “It’s expensive and it’s not good for the environment.”

All of Eden Prairie’s plow operators are smart-salt certified through the state and the Pollution Control Agency, Ellis said. “Which means they’ve gone through training about limiting the amount of salt that they use and only using it where necessary and understanding the proper application rate,” he said. “That’s something that is important for us.”

Who gets plowed first?

The first priority during snow storms is to clear major arterial streets – think Prairie Center Drive – followed by collector streets that intersect with them, Ellis said.

Also considered a priority on school days are smaller streets, such as Braxton Drive, that lead to Cedar Ridge Elementary School.

Then come regular residential streets and, finally, cul-de-sacs.

“The goal is to finish all of the city at once,” Ellis said. The routes are set up to be as equal in mileage as possible to help make that happen, he said.

At the same time, the city’s parks department is plowing sidewalks and trails, including those adjacent to county roads.

During a snow event such as the one on Jan. 4-5, both departments work together, Ellis said.

“We’ll send some of our streets guys over and vice versa,” he said. “But we also have staff from the utility division that help with snow removal and the fleet division as well. We have some of our mechanics that hop in a plow truck because when we get an event, it’s really all hands on deck.”

The division’s goal is to have all streets clear nine hours after a snow event occurs, Ellis said.

“But we beat that goal,” he said. “I can’t think of the last time we were unable to meet that goal. It’s usually much less than that. If it’s a one-inch or two-inch [snowfall], it’s probably a five hour effort.”

Overnight snow means plowing starts at 3 a.m. “We can hit most roads before the rush hour,” Ellis said. “If it’s an all-day event, then we are working a minimum of 12 hours, sometimes a little bit longer. We want to be able to leave the roads in good condition, but also give our operators a chance to go home and get a few hours of sleep.”

Hennepin County is responsible for clearing county roads such as Flying Cloud Drive (County Road 61), Valley View Road (County Road 39) and Blake Road (County Road 60). The Minnesota Department of Transportation (MnDOT) handles major roads, such as I-494 and highways 169 and 212.

Belly plows and parking woes

Eden Prairie tries to avoid problems similar to those currently being experienced by St. Paul. There, streets became snow-packed which then turned to ice. The city is now trying to clean up the mess.

It isn’t working very well, according to news reports.

Eden Prairie streets don’t usually have that problem, Ellis said. With pre-treated streets and quick reaction times, most streets are cleaned down to the blacktop by the time city plows complete their work, he said.

Upgraded equipment has helped that process as well, he said. In addition to the front and wing plows on the large vehicles, some are equipped with a special piece of ice-scraping steel.

“Some of our trucks have a third plow,” Ellis said. “They’ll have what we call a belly plow. It’s between the front axle and the back axle. It’s right in the middle of the truck and you get the full weight of the vehicle on that plow to scrape the ice.” Front-mounted plows often will pop up over the top of the ice, he said.

But even in a suburb with wide residential streets, cars left parked in the street during a snow emergency is problematic for plow drivers, Riley said.

“If someone calls to tell me that their road wasn’t plowed, I can go in [to Precise],” he said. “Now, my guys are pretty good. If there are cars and they can’t pass, they call in to let me know so I can tell [residents]that their road was impassable.”

Ellis said cars can be ticketed and towed if they aren’t moved during a snow emergency, but the city first tries to notify their owners. Police officers will even knock on doors, he said.

“Most of the time the issue is resolved that way,” Ellis said. If it isn’t, both Riley and Ellis said residents can call the streets maintenance division to request the removal of snow left in the roadway due to snowbirds.­­­

The drivers

Plow drivers – especially newer ones – prepare for winter snow plowing by driving their routes and learning their idiosyncrasies.

“We give them time behind the wheel, they’ll go out and learn their routes,” Ellis said. “They’ll even use markers sometimes if [there’s] a jog in a road. They’ll put wooden lath behind the curb, just so they have a visual cue.”

New drivers occasionally will dig up some sod, Ellis admits.

“We always go out in the spring, once all the snow is melted and do sod repair,” he said. “They’ll put in some black dirt, re-seed it. We will own those mistakes.”

All of the technology, such as AVL and the weather reporting system, help the department do its job, Ellis said.

“[So] do the modernized snowplow equipment and the city’s brine-making system,” he said. “But at the end of the day, it is our plow operators and the street division manager who really get the work done. Regardless of how bad the road conditions are, whether it’s a holiday or if it’s … in the middle of the night, our snowplow team always answers the call and works as long as it takes to make our streets safe.

“I truly believe they are the best in the business.”

Give us room

Schmidt, who lives about 28 miles west of Eden Prairie in Norwood, knows folks can be in a hurry to get home during a snowstorm, but he had one request for motorists.

“Give us some room,” he said. “We’re there to help [you]. Don’t try to get in front of us. People don’t understand how long it takes to stop these things. We’re just trying to clear the roads and make them safe.”