The Idaho Transportation Department’s (ITD) mission is clear-cut: Your Safety. Your Mobility. Your Economic Opportunity.

More than 1,700 employees ensure the movement of interstate commerce, visitors, and 1.6 million residents all year round. In winter, this is easier said than done on 12,000 lane-miles of largely remote highways in a sparsely populated state and terrain ranging from valleys and mountains to plains and highlands.

Recently, they challenged themselves to set up systems that verify the effectiveness of snow and ice control operations.

To find out how much deicer is being applied, the department is installing electronic spreader controls on all snowplows. Made by Minneapolis-based Cirus Controls LLC, the SpreadSmart Rx system with 7-inch color touch screen regulates application rate based on vehicle speed, location, and temperature; and measures the amount and type of material, enhanced with GPS location data and nearly real-time reporting.

When combined with data from 106 Vaisala road weather information system (RWIS) monitoring sites, the result is a sophisticated, integrated, and calibrated performance measurement system.

The department has installed the spreader control system on 224 snowplows and expects to finish equipping all 450 snowplows within two years. The cost for each unit is $3,500 to $4,500.

Funding for the award-winning Winter Performance Measurement system was provided by pilot and statewide funding sources. The pilot program was funded by ITD’s capital equipment replacement budget. Rolling the program out statewide was funded by an IDT capital equipment budget allocation based on the 10% to 20% materials savings achieved during the pilot program.

“Calibrated performance measurement is an integral part of our winter operations,” says ITD Mobility Services-Winter Maintenance Coordinator Dennis Jensen, who spearheaded the system’s development.

Each of ITD’s RWIS sites uses sensors to measure air temperature, wind speed and direction, and precipitation. The sites also use pavement sensors, cameras, and lasers to measure the thickness of individual layers of ice, snow, or water on road surfaces. The cost of each site is $60,000, including installation.

“RWIS data allowed us to compare events across the state and pinpoint similarities,” says Jensen, who received the American Association of State Highway and Transportation Officials’ Alfred E. Johnson Achievement Award in December 2014 for his work on the system. “Integrating controllers and GPS-based spreading data with that gives us a window into our operations that didn’t exist before.”

Managers can see the treatment executed at each RWIS location and match material application data and timing to road surface data, before and after treatment, to evaluate the effectiveness of a particular treatment approach.

“We can see how well we’re doing at preventing and removing ice from roadways,” says Jensen.

Next page: Mobility up, accidents down


Mobility up, accidents down

“Our pilot programs demonstrated we could save $600,000 a year by implementing the control system statewide,” says Jensen. “Based on our projected return on investment — that the units would pay for themselves in two to three years — we received a special appropriation to equip all snowplows.”

ITD’s mobility index is defined as the percentage of time a traveler’s movement isn’t significantly impeded.

District Two (D2) was the first of six districts to install spreader controls. Reviewing treatment effectiveness along with timing, managers realized they needed to modify practices to meet the state’s mobility index goal of 55%. They critiqued operations by evaluating data from the two databases and then compared effort against accomplishment. After significantly changing material selection, timing, and application rates, the district achieved a 70% mobility index this season.

“The technology has made a huge difference in operational planning,” says Jensen. “The D2 foremen are using both systems heavily, and this year’s accomplishments reflect that.”

Combining the two technologies has also made roads safer.

“Based on our first small samples of data, we’ve seen the number of accidents going down,” says Maintenance Services Manager Steve Spoor. “The trend is definitely in the right direction. We’ll continue to make stronger correlations between efforts and results, thanks to empirical data.”

Paul Mortell is president of Cirus Controls LLC of Brooklyn Park, Minn. E-mail