CalTrans’ Strategies for Safe Winter Maintenance

California has both sun- and snow-belts, and 
some areas change from one to the other in short order.

by Karen Stidger, Contributing Editor

Like a roller coaster track running across the peaks and valleys of California’s Coast Range, State Highway 299 West, also called Trinity Highway, is the principal route connecting the heat of the northern Sacramento Valley and the cool of the Redwood coast. Scenic byway by summer, surprising and fearsome by winter, this heavily traveled 140-mile journey can be filled with rockslides and icy switchbacks with few turnouts or passing lanes. To address road conditions and driver safety on this two-lane highway, CalTrans uses a proactive combination of equipment, chemicals, and manpower.

Scenic byway

It doesn’t matter if drivers are trucking ocean crab or forest timber, vacationing in their RV, or taking a convertible for a day at the beach, chances are they will come across one of Milt Apple’s CalTrans road crews on their drive across Highway 299. Apple, a 30-year CalTrans veteran, is highway maintenance area superintendent for Weaverville Territory, one of the most work-intensive areas in the state. The territory includes 58 centerline miles on Highway 299 running through Shasta and Trinity Counties.

Highway 299 West sits on a ledge above the rugged Trinity River, known for its Salmon and Steelhead fisheries and the whitewater that attracts rafters and kayakers. This scenic route alternates between 3,200-foot forested peaks and 500-foot valleys of manzanita. Winters can leave snow, snow followed by rain, rockslides, persistent fog, or black ice on the narrow highway as it weaves in and out of view of both sun and driver.

Buckhorn Summit is the highest peak at an elevation of 3,213 feet. Apple calls it “old faithful” because “every winter it gives you material.” The rain and freeze/thaw cycles often cause decomposed granite rockslides of up to 5,000 tons. If rain follows a snowstorm, the runoff can double, causing flooding. When it’s not raining or snowing, lingering fog wets the road and holds in thermal heat. Once the fog burns off at mid-morning, the ambient temperature can drop, leaving icy blacktop.

On call 24/7, normal scheduling consists of two 10-hour shifts, four days a week. Crews go to 12-hour shifts during storm season, making Buckhorn Summit the most costly overtime area in the territory.

All-season equipment

Maintenance crews for Highway 299 have no dedicated snow equipment. Since the weather varies so much, it is more cost effective to use all-season equipment. For example, the district has two dump trucks that are used for hauling, sanding, and pulling trailers. A snowplow attaches to the front for winter plowing and a tank loads into the back for anti-icing applications. The truck doubles as a shadow vehicle for worker protection.

In addition, crews operate graders to clear roadside debris, maintain shoulders, and clean ditches. When needed, a nose plow attachment heels back snow.

For snow removal, however, Apple prefers using loaders because they give the driver better visibility. He also finds loaders are quicker when clearing intersections and private driveways that have been blocked with plowed snow.

Using the right chemical

The chief strategy employed in keeping the road clear is prevention of both ice formation and snow bonding.

To prevent ice from developing, crews use an anti-icer made of magnesium chloride with a corrosion inhibitor and cut with water. Thirty gallons per lane mile is applied. After spraying, the water evaporates. The remaining anti-icer works down to 10 degrees F, which is much lower than normal night temperatures in the area. Depending on the amount of fog experienced, an application can last 10 days to two weeks. This chemical is environmentally safe and cheaper than deicing, an important factor in a world of shrinking budgets. Ice prevention is also more cost effective for CalTrans stakeholders who depend on clear roads to maintain commercial delivery schedules as well as leisure travel.

In the past, Apple’s crews used 2,000 tons per year of cinders and sand. Anti-icing has cut this number to 100 tons per year, used mainly for isolated problem areas. When sand is used, Apple has found that not mixing sand and cinders gives a more even application and a more constant result. The downside of these products is their inability to remain on roads through periods of heavy traffic. Cinders wind up in culverts and under guardrails and require clean up, adding to maintenance costs. In addition, some amount eventually finds its way into the river fisheries.

Anti-icer use gives the additional benefit of shining like wet or icy pavement, encouraging extreme drivers to slow down.

In addition to the use of anti-icers and sand, crews also use salt. Applied at the onslaught of snowstorms, salt functions as a bond breaker, preventing the pack from tightening and enabling graders to continue to peel.

Consistent with this cost-effective, proactive strategy, recessed centerline pavement markers are installed every 24 feet during highway construction. In spite of the high cost of $15 apiece, CalTrans believes it is important to install markers that will survive plows and graders and will assist drivers in nighttime and foggy conditions on this dark road.

In addition, for the past three years, CalTrans has benefited from a Road Weather Information System. Sensors imbedded in the road in problem-associated areas relay data about road and air temperature, percent of chemical residue on the road, wind speed and direction, and sub-grade temperature. Data is used to provide local weather forecasts.

Dedicated manpower

An important ingredient in winter road maintenance on Highway 299 is summer vegetation management, all of which is performed by manual labor. Vegetation management helps by slowing winter road shade, opening shoulders for snow removal, making deer visible to drivers, and preventing fires.

According to Jeff Kiser, CalTrans maintenance manager, “Milt Apple keeps the highway up just like it was his own yard.” Apple’s goal is to manicure without losing the natural look and aesthetics of the area. No herbicides are used in Trinity County along the river.

Trinity River Conservation Camp inmates join CalTrans workers in their efforts to trim trees and cut brush. In this all-important alliance, CalTrans provides the fuel for the camp’s equipment. Apple says of the hard-working inmates, “We couldn’t get all the work done without them.”

During winter storms, manual chain stations are set up, requiring and verifying drivers’ use of chains instead of studded or snow tires. CalTrans knows that one car out of control will shut down the entire road.

Looking at the future

CalTrans is very successful at preventing icepack and managing storm conditions along Highway 299. Several projects for the future will act to sustain this success. According to Apple, “All new construction in snow country has sand traps designed into them.” This road feature will make management of sand and cinder buildup easier.

In addition, CalTrans is working on a Rural Intelligent Transportation System. They plan to use the system first at their traffic management center. When it is made available to the public in the next couple of years, it will let travelers check real-time road conditions online and at roadside stations.

Finally, early stage environmental and engineering work is in progress on a $100-million project to bypass Buckhorn Summit and its 8-mile corkscrew ascent.

As populations grow in the coastal and north valley areas, Highway 299 and Apple’s maintenance crews will continue to play a major role in the pleasure and safety of travelers’ activities.

Photos courtesy of CalTrans

Reprinted from Better Roads Magazine
August 2002

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