Snowplow operators face harsh driving conditions and must also deal with fatigue and drowsiness. A recent multi-state research project identifies factors that cause driver fatigue in snowplow operators and recommends cost-effective solutions to help reduce it.
Clear Roads – a winter maintenance research initiative – surveyed 33 member states to gather data on snowplow operators’ experiences with fatigue. More than 2,000 snowplow operators from 23 Clear Roads states responded.
Nearly all the respondents (94 percent) reported feeling fatigue at some point while operating a snowplow during winter weather events. The majority of vehicle operators (59 percent) reported their shifts of 8 to 16 hours included both daytime and nighttime segments. Smaller proportions reported that they worked primarily during the day (22 percent) or primarily at night (18 percent).
Survey results also indicated that more experienced operators were more prone to fatigue, and those who worked shifts lasting longer than 16 hours reported significantly higher levels of fatigue.
Based on the results and analysis, researchers ranked the in-cab and external equipment that caused fatigue. The top four equipment-related sources of fatigue were bright interior lighting, standard windshield wipers, misplaced or insufficient auxiliary lighting, and old or uncomfortable seats.
Among the non-equipment-related sources of fatigue, the most commonly reported factor was silence (lack of music or talking), followed by length of shift, lack of sleep, and insufficient breaks.
Using the same ratings, researchers developed a list of recommended actions that can be implemented by agencies to decrease driver fatigue. The recommendations were based on a comparison of each solution’s costs (equipment costs and potential risk of adversely affecting fatigue) and benefits (effectiveness in reducing operator fatigue).
Among the researchers’ equipment-related recommendations, the most cost-effective called for adding:
A CD player or satellite radio to deliver music or speech, preventing short-term fatigue.
Dimmable interior lighting to reduce reflections on the windshield and windows, providing better visibility.
Dimmable warning lights to reduce back-reflected light from the warning lights, lowering visual distraction.
Snow deflectors to reduce the amount of snow blown on the windshield, providing better visibility.
Heated windshields to reduce snow and ice buildup on the windshield, providing better visibility.
Non-equipment solutions included encouraging adequate breaks, limiting shifts to 12 consecutive hours when feasible, developing a fatigue management policy, encouraging a healthy lifestyle, and designating dedicated rest locations for operators.
According to the report, both the equipment-related and non-equipment-related solutions provide easy and quick corrective actions that agencies can implement immediately to increase the health and safety of snowplow operators.
The Minnesota-led Clear Roads winter maintenance program has profiled six state agencies’ experience with automatic vehicle location (AVL) and GPS in winter maintenance fleets to share best practices with other cold weather states. Strong support by these agencies drives robust use of the technologies for location tracking, asset monitoring and planning for future storms.
AVL and GPS have been widely embraced in winter maintenance operations by transportation agencies around the country. But tracking vehicle locations for operational and safety reasons only scratches the surface of these systems’ potential uses. Many agencies also use AVL/GPS to collect extensive data for planning, operations, safety and inventory tracking to improve efficiency and response strategies.
Need for Research
AVL and GPS have been used in winter maintenance operations for several years. While most agencies use AVL/GPS for tracking vehicle location, the technologies offer operational, safety, inventory and planning applications, as outlined in a 2016 Clear Roads synthesis report. How agencies actually employ these automatic data collection technologies has remained less well-known.
Objectives and Methodology
The goal of this project was to explore agencies’ experiences and best practices in planning, implementing and using AVL/GPS technologies for winter maintenance activities. The investigation began with a survey of state and selected metropolitan transportation agencies about their level of commitment to AVL/GPS implementation and the data the agencies collect, use and share.
Investigators worked closely with Clear Roads to identify levels of usage of the technologies. Then they selected six agencies that represented various commitment levels, interviewed staff from each agency and gathered relevant documents about agency use of AVL/GPS. Using the information obtained during the interviews, researchers prepared case studies of each agency and recommendations for other agencies to further implement and utilize the technologies.
Twenty-seven of the 38 agencies that responded to the survey reported using AVL/GPS to automatically collect winter maintenance data, while 36 of the 38 agencies indicated plans to add or expand use of the technologies in the future. Based on feedback from these agencies, researchers developed three levels of AVL/GPS use and categorized agencies according to the appropriate level.
Tier 1 agencies employ AVL/GPS for basic location tracking or monitoring. Utah DOT has mounted AVL/GPS behind the dashboard of every snowplow and incident maintenance truck (vehicles that assist stranded motorists on Utah’s roads and highways) in its fleet. The system connects with plow position sensors, tracks idling time and traveling speed, and reports plow locations on a publicly accessible website.
Tier 2 users add basic data collection, equipment integration and system reporting features to Tier 1 usage, often in concert with other technologies. Washington State DOT’s Tier 2 usage integrates AVL/GPS with spreader controllers, plow position sensors, and air and pavement temperature sensors in 80 percent of its fleet to track material use, road weather and operational analysis data. Michigan DOT integrates AVL/GPS with spreaders, plows and dashcams in 94 percent of its fleet to track vehicle location, vehicle diagnostics and material use, and to use for operational analysis and information sharing with the public.
Tier 3 agencies conduct complex data collection, integration and reporting activities with AVL/GPS as part of a suite of instruments and applications that collect and transmit data to users, the agency and, in some cases, the public. Colorado DOT (100 percent of its fleet), Nebraska DOT (33 percent) and Wisconsin DOT (53 percent) link AVL/GPS to data collectors, plows, spreader controllers, pavement and air temperature controllers, and other equipment. Each agency tracks vehicle location, material use, treatment recommendations, vehicle diagnostics and data for operational analysis, among other uses. Colorado and Wisconsin DOTs share data with a maintenance decision support system; Colorado DOT also shares information with the public.
Keys to success with AVL/GPS include obtaining full organizational and financial support from agency management, piloting the system with vendors and operators to identify objectives for use, providing operators with training that emphasizes the technologies’ operational and safety benefits, involving agency mechanics in installation, and using the system data for real-time adjustments to maintenance and resource-allocation strategies.
“The recommendations were very constructive— everything from planning and decision-making to how to best collect data and use it for performance measurement,” said Project Champion, Patti Caswell, Oregon Department of Transportation.
Benefits and Further Research
The final report offers information that will be useful to prospective and current adopters, describing best practices in AVL/GPS planning and implementation, procurement, installation, training, data collection and utilization, and operations and maintenance.
Future research may evaluate methods for integrating technologies from various manufacturers into a cohesive, operational system. Turnkey options remain limited, and integrating sensor, camera, data collection and GPS presents a number of technical challenges. Related study may evaluate communication terminology for uniform data
sharing between agencies. Follow-up research could also identify the costs and benefits of AVL/GPS to quantify the value of these technologies to users.
Connected vehicle technologies, which use roadside units to communicate with other roadside units and wirelessly with vehicles, offer potential applications for real-time data collection and sharing among plow operators and other stakeholders. The relative value and ability to implement such systems may warrant research and comparison to
The Minnesota-led Clear Roads winter maintenance research program has developed a set of training tools—two videos and two quick reference guides—to promote liquid roadway treatments and provide practical guidance for agencies implementing a liquid anti-icing/deicing program.
Many agencies use liquids such as salt brine as anti-icing treatments to prevent ice from forming on roadways. But the application of salt brine as a deicing treatment during or after a winter storm has been slower to catch on. When used in the right conditions, liquid deicing treatments are as effective as granular sodium chloride while using less salt, but liquid-only routes are used by only a minority of winter maintenance agencies. To get the word out about the benefits of using salt brine and other liquids as both anti-icing and deicing treatments, as well as provide practical information about liquid application procedures, Clear Roads initiated this project.
Need for Research
While there is a wide range of information available about the use of brine and other liquids for anti-icing and deicing, there was a need to offer clear, comprehensive guidance in a single resource and to provide training tools for implementation.
A 2010 Clear Roads project helped lay the groundwork for this effort by identifying the parameters for effective implementation of liquid-only plow routes. That project produced a quick reference guide that outlined the conditions when liquid deicing treatments are most effective and provided application rates and implementation recommendations. A follow-up study was needed to update this guidance and to develop tools to facilitate the implementation of liquid-only plow routes.
Objectives and Methodology
This project’s goal was to produce a set of training tools—two videos and two quick reference guides—explaining the benefits of liquid-only plow routes, outlining procedures for implementation, and addressing misinformation and misconceptions. The project had two objectives:
• Inform agency decision-makers and the general public about the benefits of liquid roadway treatments while dispelling common myths.
• Provide practical guidance for maintenance managers and plow operators, and for agencies looking to start a liquid-only program.
Researchers began by conducting a literature review of research and practices related to liquid-only plow routes. They then sent an online survey to agencies in 27 states to determine which agencies used liquid-only roadway treatments. The survey yielded 92 responses from state DOTs and county and municipal highway departments. Follow-up interviews with 14 survey respondents gathered information about types of roads where liquid-only routes are used, application rates and material usage, brine making and storage, cycle times and loading times, and public perception and environmental concerns.
Of the 92 survey respondents, 30 indicated that their agency had a liquid-only route. In general, these respondents reported that liquids are more effective than solid deicers in
the right circumstances. Based on the information gathered in the survey, interviews
and literature review, researchers created two videos:
A shorter video for agency decision-makers and the general public that discusses the benefits of liquid-only treatments while addressing common misconceptions (particularly misinformation about corrosion and salts in the environment).
A full-length video for practitioners that includes information from the short video as well as tips for starting a liquid-only program, discussion of equipment types, and recommended usage parameters and application rates.
To complement the videos, researchers created two 2-page quick reference guides—a Start-Up Reference Guide to help agencies gain buy-in for a liquid-only program and a Technical Reference Guide with more detailed usage parameters, application rates and general tips.
“To effectively get the word out about liquid-only road treatments, there was a need to put the right message in front of the right audience in a compelling way and to dispel myths and misconceptions. These guides and videos do just that,” said Project Co-Champion, Scott Lucas, Ohio Department of Transportation.
The videos and quick reference guides communicate key information about liquid-only routes, including:
Appropriate use: Liquids are especially effective during light snowfalls and at milder temperatures. Agencies also use liquids to loosen packed snow for plowing; during high winds when granular salt may blow off the roadway; and as anti-icing treatments before freezing rain.
Benefits: Liquid deicing treatments use less salt, which leads to cost savings and reduced environmental impact. Liquids begin to work immediately, and they stay on the roadway (no bounce or scatter).
Misconceptions: Liquid applications of salt brine do not cause more corrosion damage to vehicles than granular salt. Granular salt must dissolve into brine on the roadway in order to melt snow and ice, so either approach exposes vehicles to salt brine. Corrosion inhibitors can help; some studies show they are more effective with liquids than solids.
Benefits and Further Research
The videos give transportation agencies modern communication tools to help target specific audiences: The shorter video is more appropriate for social media distribution and sharing, while the longer video is more useful for agency staff training and cross-agency communication. Both the quick reference guides and the videos will help agencies garner support for liquid-only programs and provide practical guidance for
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:
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.
CTS aired a new video—”How does University of Minnesota research make a difference?”—at its Annual Meeting and Awards Luncheon on April 6.
The video highlights a variety of U of M research initiatives from 2014-2015. Projects featured focus on hardier roadside grasses, tribal transportation safety, left-turn safety, maximizing system performance, clear roads in winter, well-rested truckers, increased transit ridership, more efficient buses, safer teen drivers, understanding travel behavior, better asphalt pavements, and healthy lakes and rivers.
Even naturally derived products like corn syrup and beet juice can impact the environment when applied to salt mixtures for winter roadways.
A wide range of products, including the ones mentioned above, are added to deicing mixes to limit the amount of salt needed for Minnesota roads each winter. However, although information is available about the corrosive properties of various deicing chemicals, less is known about the toxicity of these compounds, especially to the aquatic environment.
Thanks to a recently completed project sponsored by the Clear Roads Pooled Fund, MnDOT winter maintenance personnel will better understand the relative toxicity of eight common deicing agents, which also include non-organics like Magnesium Chloride, Calcium Chloride and Potassium Acetate.
“Because the state has been trying a lot of different alternative chemicals, we wanted to get a better handle on the environmental impacts,” said MnDOT engineer Tom Peters, the technical liaison for the 26-member, Minnesota-led pooled fund for winter maintenance research.
In January, researchers plan to release a concise summary of the toxicity rankings to help winter highway maintenance managers consider both expected levels of service and potential harm to the environment when selecting a deicer.
Minnesota is the lead state for the Clear Roads Pooled Fund, which conducts rigorous testing of winter maintenance materials, equipment and techniques. Other recent and upcoming research (see our Technical Summary on the program) includes a winter maintenance cost-benefit analysis toolkit, snow removal techniques at extreme temperatures and environmental factors that can cause fatigue in snowplow operators.
You can learn more about Clear Roads via the project’s e-newsletter.