The level of effort category includes assigning more people and equipment to higher priority routes, providing more or less effort during certain time frames, and varying the number of people and equipment providing treatment in relationship to the predicted severity of the event, according to the NCHRP report. “The priority of treatment category includes giving first and/or more frequent treatment to higher traffic routes, high-accident/problem locations, commercial/business locations, school bus routes, transit routes, health facilities, firehouse locations and schools,” the report notes. Some highway agencies use a system of providing treatment on a highway priority basis whereby the next lower category of highway is not treated until higher category roads are in “satisfactory” condition, according to NCHRP Report 526.

“A good way to define LOS is in terms of results at various points in time,” the report notes. Examples include maximum accumulation of snow on highways during a storm, absence of pack or bond during a storm, bare/wet pavement (x) hours after end-of-event, plowed and sanded (x) hours after end-of-event, friction number > (y) (x) hours after end-of-event, road plowed and road passable, according to the report.

The NCHRP report defines two fundamental approaches for highway agencies to use when assigning their LOS goals. The first is to evaluate existing resources and direct them toward providing a balanced LOS on a priority of treatment basis. “This is realistically the more common approach,” the report notes. The second, and preferred, approach is to assign pavement condition goals at intervals within and after a “design storm” of “x” inches of snow per hour to the various priority elements of the highway system. “Using this, and production rate (lane-miles per hour) of equipment (including deadheading and reloading) in both the plowing and materials-spreading modes, the necessary personnel and equipment can then be determined to provide the desired LOS,” according to the report.

Bill Hoffman, chief maintenance and operations engineer for the Nevada Department of Transportation (NDOT), says of the idea behind LOS: “As a whole, we are trying to balance the safety of the traveling public, mobility and reliability so it doesn’t take you one hour on one day to get somewhere and four hours the next day,” Hoffman says. “We’re trying to balance what we should be doing [along with] customer satisfaction. These are what you call levels of service.

“We are trying to do the absolute best we can, but if that means dumping 500 pounds per lane mile and it just ends up in a ditch of in streams, that’s not good,” Hoffman continues. That’s why agencies need to use technology and best practices “to help us over the hump,” Hoffman adds.

Keeping Tahoe Open and Blue

Lake Tahoe is at about 6,200-foot elevation, and to get there from Reno it’s necessary to go over an 8,900-foot pass. “The [winter maintenance] methods and operations are totally different,” he says. “Different [anti-icing and deicing] chemicals work at different temperatures, and you have to balance the type of chemicals you use.”

However, it’s particularly challenging to practice responsible winter maintenance for sustainability and still achieve a good LOS for the bridges and roads because of environmental concerns around the Lake Tahoe area. The Tahoe Regional Planning Association has national support to keep Lake Tahoe blue. “The last thing we need to do is dump tons of salt into Tahoe . . . it’s not a good move,” Hoffman says. “We are also trying to cut back on the amount of sand we are using, too, because of the sedimentation that it adds to streams, ponds and other lakes.”

In the northern part of Nevada, near Lake Tahoe, Hoffman says, the I-80 Corridor Coalition (www.i80coalition.com) was started. The coalition is composed of Nevada, Utah, California and Wyoming, with hopes that Nebraska will soon join. “Every year, the coalition gathers and discusses how to do things better during the winter … how we can connect and share information between traffic management centers in the states and how to do better winter operations,” Hoffman says. This means discussing levels of service, what materials to use when and how it relates back to sustainability. “There are the three overlapping bubbles when it comes to winter maintenance and sustainability – societal (i.e., mobility), environmental and safety,” he points out. “Where they all overlap is level of service. Maybe you don’t need to maintain the roads at level of service ‘A’ at all times. Maybe it can drop to a ‘B’ or a ‘C’ if it’s safe and people are getting through with minimal delay. That’s where the department’s economic piece comes in.”

Hoffman says the question, “Are you being the most efficient and effective?” needs to be asked. “The societal piece is multidimensional. It’s also the cost of business the DOTs have to go through with clearing the roads.”

A Holistic Approach

Paul Pisano, team leader for the Federal Highway Administration’s (FHWA) Road Weather Management Team, says a “holistic” approach needs to be taken. “You can’t approach sustainability piecemeal,” he says. “It’s more a matter of framework – thinking about it from the beginning to the end.”

Approaching it as a framework instead of in just segments provides a “clearer focus,” Pisano says, so that people who have been wrestling with budgets and with safety have a better idea of what is being done and why. The idea of sustainability within the winter maintenance world is neither new nor revolutionary, but it just has been conducted in more implicit ways than explicit, Pisano says. By this, Pisano says he means that people on the maintenance side of things are thinking about long-term impacts and sustainability; it’s just that no one ever called it that. By approaching it in a more explicit manner (i.e., structured way), it increases the likelihood of success, he says.

“We’re not going to change the world with it, but it gives a more structured way to look at things,” Pisano says. “It’s not just, ‘What are we doing today?’ but ‘What am I doing today, and how do I take into account what will happen next year?’ This helps when you look at societal impacts vs. economy vs. safety. You can’t focus on one without recognizing how it will affect others. There is a balance that needs to be found.”v