Icy, cold and expensive
By Dale F. Doughty, C.G., MaineDOT Director of Maintenance & Operations and Brian Burne, P.E., MaineDOT State Highway Maintenance Engineer
MaineDOT has a fleet of roughly 400 plow trucks that are used to control snow and ice on approximately 7,600 lane miles of Maine’s state roads. In addition, another 700 lane miles are contracted with municipalities and private contractors. Like most entities that control snow and ice on high-speed, high-volume highways, MaineDOT uses an anti-icing approach that is very effective for returning roads to bare pavement soon after a storm ends.
Maine typically receives an annual snowfall of roughly 60 to 80 inches in the southern and eastern parts of the state and about 110 to 120 inches in the western mountains and northern areas. Average winter temperatures are usually between 13 F and 23 F degrees, but minimum temperatures into the -20s F and below are not uncommon. MaineDOT usually plans on an average of 30 “treatable” events each winter. This number has a broad range across the state, from western mountains to the southeastern coast.
Overall, the winter of 2013-2014 has been icy, cold and expensive. When only considering the average of 33 treatable events that we have received to date (Mid-March), this winter appears to be only 10 percent worse than average. However, when considering the nature of the actual events, as well as the deep freeze that has often followed them, it becomes much more apparent why overall costs are running 20 percent higher than normal.
Material usage is often a point of focus in any snow and ice program. This is not only due to the fact that material costs account for one-third of winter expenditures, but also because materials can have a direct impact on safety and a lasting impact on the environment.
Like MaineDOT’s snow and ice program as a whole, material selection and use is a delicate balance between cost, safety (level-of-service), and the environment. Unfortunately, every material has its drawbacks. Rock salt is by far the most commonly used material due to its effectiveness at depressing the freeze point of water combined with its relatively low cost. However, rock salt is temperature dependent and as the temperature drops, it becomes less effective. Therefore, this winter we had used roughly 120,000 tons of salt by mid-March and there are more storms to come. In comparison, we normally anticipate using about 100,000 tons in an average winter.
The following graph indicates how overall material usage has changed since 1997, how that relates to current-day material costs (projected back in time) and, in recent years, how the average number of storms have varied. Note that this year’s costs, as of the middle of March, may approach the costs of 07-08 and 10-11. Yet, as noted above the number of treatable events is significantly less. Repeated periods of wet icy precipitation, timing of storms and deep cold swings all contribute to the cost of this year’s winter.
MaineDOT works closely with its northern tier state counterparts to ensure that we are making the most of the latest technologies, equipment and strategies. Participation in the Clear Roads organization – a pooled fund winter highway operations research group – has been an essential link to the national and global snow and ice fighting knowledge base. The Clear Roads web site may be visited at clearroads.org. One recently completed project captured the winter severity across the continental United States. The following graphic shows that Maine is among those states with the most challenging winters based on a number of environmental factors.
MaineDOT’s drive to continuously improve its snow and ice program spurs numerous research projects during the winter months. This research involves everything from new equipment, to new materials, or new techniques. In recent years, our research has focused on the snow fighters primary tool – the snow plow. In addition, MaineDOT has been expanding the use of GPS technology to better track the location of trucks and materials used. To date, nearly 25 percent of the snow plow fleet has been outfitted with this technology and we will continue to expand this percentage over the next six to seven years.
Finally, we invite you to join us in thanking Maine’s thousands of snow fighters: state, local and private. The technology described above saves us all money and produces a better, safer service but, it has made their jobs much more complicated. Even with technology advancements, snow fighting remains physically demanding. When the rest of us were preparing for this year’s Christmas and New Year Holidays, most of those snow fighters were on the road, day and night away from their families, keeping us all safe. It is that dedication that keeps Maine “Open for Business” for the five months of winter.
FMI: To learn more about MaineDOT’s snow and ice program, please visit http://www.maine.gov/mdot/winterdriving/snowandice.htm.