Tag Archives: snow plow

Winter Decision-Making Crosses State Lines

Winter weather events have a regional and often national impact. “Storms never stop at the state line,” said Tom Peters, research and training engineer, MnDOT Maintenance Operations. “That’s why it’s so important for us to know about winter maintenance efforts around the country, and particularly at neighboring states with similar climates.”

MnDOT leads the Clear Roads Transportation Pooled Fund Project (clearroads.org), a national winter maintenance research consortium. In 2015, Clear Roads launched a national survey to collect and report the annual winter maintenance operations of state DOTs. The effort included nearly 50 data points related to equipment, materials and costs.

The results, which are available at clearroads.org/winter-maintenance-survey as a Microsoft Excel-based spreadsheet, are available at no cost for users to examine, analyze and parse as needed. Beyond the raw data, the spreadsheet includes calculated statistics and an interactive map for plotting key metrics.

The results quantified much of what was known only anecdotally and provided useful, actionable data. “Data trends by geographic region and over time let us make more informed operations decisions,” Peters said. “We can also draw on this information to communicate with management, elected officials and the public about how MnDOT’s winter operations fit in a national context.”

As the lead state, MnDOT commits significant administrative time and attention across the agency to Clear Roads. “It’s rewarding and satisfying to see such a useful product as one of the payoffs for all this effort,” Peters said.

Additional data collection for the 2015-2016 winter season is already complete. Look for an update to the online database later this year.


Research in Progress

Clear Roads has nearly a dozen research projects in progress, including:

See all of Clear Roads’ current research projects at clearroads.org/research-in-progress.


What’s Next?

At its September meeting in Omaha, Nebraska, the Clear Roads Technical Advisory Committee funded five new projects:

  • Utilization of GPS/AVL Technology: Case Studies
  • Standards and Guidance for Using Sensor Technology to Assess Winter Road Conditions
  • Emergency Operations Methodology for Extreme Winter Storm Events
  • Weather Event Reconstruction and Analysis Tool
  • Training Video for the Implementation of Liquid-Only Plow Routes

What is Clear Roads? 

Clear Roads is a 33-member pooled fund program dedicated to winter road maintenance research. Led by MnDOT, Clear Roads projects evaluate winter maintenance materials, equipment and methods; develop specifications and recommendations; study and promote innovative techniques and technologies; and develop field guides and training curricula. Learn more at clearroads.org.

Driver-assist system helps keep plows on the road

Darryl Oeltjenbruns, snowplow driver in District 7, operates the only driver assist system, or DAS, equipped snowplow in the state. The system helps snowplow operators see road alignments and features such as turn lanes, guardrails and road markings. (Photo by Chase Fester)
Darryl Oeltjenbruns, snowplow driver in District 7, operates the only driver assist system, or DAS, equipped snowplow in the state. The system helps snowplow operators see road alignments and features such as turn lanes, guardrails and road markings. (Photo by Chase Fester)

By Sue Roe, MnDOT Communications

Southwest Minnesota has the highest average wind speeds in the state—bad news for MnDOT snowplow operators who often drive in low visibility to clear roads.

“We have more days when the wind blows than when it doesn’t,” said Chase Fester, MnDOT District 7 transportation operations supervisor. “We struggle with the wind.”

That’s why District 7 is piloting a snowplow driver-assist system (DAS) developed by University of Minnesota researchers to combat the blowing snow and fog that often cause zero visibility. The DAS helps snowplow operators see the road alignment and features, such as turn lanes, guardrails, and road markings. Even in less extreme winter weather, snowplow operators gain assurance of their lane location using the system.

The driver assist system displays a white box on the screen when an obstacle, or in this case a mailbox, is located. If the object appears in the lane, such as a car stuck in a snow drift, the box turns red and gets bigger as the snowplow gets closer to the object. (Photo courtesy of MnDOT District 7)
The driver assist system displays a white box on the screen when an obstacle, or in this case a mailbox, is located. If the object appears in the lane, such as a car stuck in a snow drift, the box turns red and gets bigger as the snowplow gets closer to the object. (Photo courtesy of MnDOT District 7)

The DAS was developed and refined over the past 20 years under multiple research projects funded by MnDOT and the USDOT’s University Transportation Center program. Professor Max Donath, director of the University of Minnesota’s Roadway Safety Institute, led the work. In addition to plows, the DAS technology has also been applied in other specialty vehicles such as patrol cars and ambulances. Numerous vehicles using the system have been deployed in both Minnesota and Alaska.

The DAS uses GPS technology and a front-mounted radar to provide an image of the road and any obstacles in front of the operator. The image is displayed on a monitor inside the cab of the plow. The system also vibrates the operator’s seat as a warning if the plow veers too close to the roadway’s centerline or fog line.

“If the driver gets within one foot of the fog line on the right side, the right side of the seat vibrates. If the driver gets too close to the centerline on the left side, the left side vibrates,” said Fester.

The vibrations continue until the driver moves back into the center of the lane. The driver can also turn off the warning feature to clear snow from the shoulder.

The DAS is currently installed in one truck in District 7. The $75,000 cost makes it difficult to install in every truck in the district or the state, although having at least one system in every district may be possible, Fester said.

Fester said the system proved its worth one day in February when blizzard conditions caused zero visibility and forced many road closures in southwest Minnesota. He was called out at 2 a.m. Feb. 8 to assist a stranded state trooper and several motorists on a 12-mile stretch of Hwy 60 between Windom and Heron Lake. Fester drove a pickup behind the DAS-equipped snowplow, driven by Darryl Oeltjenbruns, to reach them.

As the DAS identified stranded vehicles on the way to Heron Lake, Fester and Oeltjenbruns checked to make sure they weren’t occupied with people. Once they made it to Heron Lake, they stopped at the community center, where the state trooper and the stranded motorists he brought in were located.

On the way back to Windom, Fester and the state patrolman continued to check on stranded vehicles as the DAS-equipped snowplow led the way. If the vehicles weren’t in the ditch, motorists drove behind the two MnDOT vehicles. If their vehicles were in the ditch, motorists rode in a Suburban that was also being escorted to Windom. After returning to Windom, the motorists were dropped off at motels or truck stops.

“When we first went out, there were about six stranded vehicles. Coming back from Heron Lake, there were about 15,” Fester said. “At one time, we had 12 vehicles in line as we drove back to Windom, driving about 10 to 15 miles per hour.”

Later that morning the DAS system was used again to locate other motorists.

“We continued to use it until about 10 a.m. or 11 a.m. that day,” Fester said. “The system worked great and kept everyone safe. It was an interesting morning.”

(Reprinted and adapted with permission from an article by Sue Roe in MnDOT’s Feb. 17, 2016 Newsline.)

Decoding the Deicers

The results of last season’s deicing study are in — just in time for our next snow.

Last winter, Minnesota State University researcher Steve Druschel set up experimental lanes at two Shakopee entertainment parks and a test site on a Mankato bridge to examine the life cycle of winter maintenance, from plowing and the application of chemicals to the drainage of chemical residue after the roadway has been treated.

What the Study Found

  • The majority of chloride appears to leave the roadway by plow ejection, vehicle carry-away or tire-spray spreading, rather than through storm drainage, even in warmer storms.
  • Pavements don’t hold chloride very long in a precipitation event, even after anti-icing/pre-treatment.
  • Deicer effectiveness. Warmer temperatures provide more melt from the deicer. Little melt was observed below
    10 degrees Fahrenheit unless sunlight provided warming, and prewetting produced no significant difference in deicer performance.
  • Dry pavements may be better candidates for pretreatment, with researchers noting that any wetness on the pavement ahead of a storm limited anti-icer effectiveness.
  • Truck traffic after deicer application was found to significantly improve deicer performance, resulting in both a wider and quicker melt.
  • Plow effectiveness. Even with different snow and temperature conditions, the evaluation of plow speed provided the same findings: snow rises higher in the curvature of the plow at higher speeds, creating a broader spray off the plow ends, and higher speeds decrease scrape quality.
Students pour water to form ice on a test lane in Shakopee.
Students pour water to form ice on a test lane in Shakopee.

What’s Next?

The research team has proposed a third phase of this project to continue their work in the field, which is expected to include further examination of the impact of truck traffic on deicer effectiveness, variations in plow setup and expanded testing under varying weather conditions and snow structure.

Related Resources

Field Effects on Deicing and Anti-Icing Performance – Technical Summary (PDF, 1 MB, 2 pages); Final Report (coming soon)

Salt Brine Blending to Optimize Deicing and Anti-Icing Performance –Technical Summary (PDF, 1 MB, 2 pages) and Final Report (PDF, 11 MB, 151 pages) (previous study)