Road Weather Management Program
photos of lightning, trucks plowing snow, an empty road before a storm, and an evacuation
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A Cleaner, Safer Way to the Slopes

By pairing an innovative weather prediction and monitoring system with an anti-icing strategy, the Nevada Department of Transportation is improving driving safety while protecting the environment. The new methods are projected to save the State $7 million over the next 25 years.

The Challenge

With its winding two-lane mountain roads and fragile alpine environment, the Lake Tahoe basin presents a tough winter maintenance challenge. Drivers headed for the recreational areas in the Sierra Nevada rely on those roads in all kinds of weather. And some of the traditional methods of handling ice and snow, such as salt and sand, can be harmful to the environment. The Nevada Department of Transportation (DOT) needed a plan that would improve driving safety and still protect the environment.

Developing the Strategy

In preparation for the 1991 winter season, Nevada DOT planned a test of the road weather information system (RWIS), evaluated and enhanced as part of the Strategic Highway Research Program (SHRP). One remote weather station was installed on a 20-km (12-mi) stretch of US 395 north of Reno.

The strategy also involved the use of anti-icing techniques in which deicing chemicals are applied in advance of a storm to inhibit ice formation.

If the system proved effective, the DOT would consider expanding the RWIS into the Lake Tahoe basin, a major tourist attraction and ski resort.

Putting the Strategy to the Test

As the first winter storm approached, the RWIS indicated that the pavement temperature in the Reno area would stay above freezing. For the field test, the southbound lanes of US 395 were treated with salt and sand while the northbound lanes were left untreated. After the storm, the two lanes showed no difference in travel conditions, as the RWIS had predicted.

Before the next storm, the RWIS indicated that pavements would become icy. This time the crews deployed their anti-icing strategy, applying liquid deicing chemicals 1 hour before freezing temperatures set in. This prevented the precipitation from freezing, making it easier to keep the roads clear of snow and ice.

What They Learned

Nevada continued to experiment with this strategy over the next two winters. The RWIS proved to be an important tool for ensuring that deicing chemicals were applied at the right time and place, making maintenance efforts more effective and reducing staff and equipment requirements.

"We used the data received from the RWIS sites to assist with crew scheduling, to plan chemical treatments, and to monitor and update road conditions," reports Rick Nelson, district engineer for Nevada DOT. "This information was previously unavailable to our maintenance supervisors and was a welcome planning tool. The accuracy of the data earned the confidence of supervisors and crews alike."

The Benefits

Based on the success of this effort, Nevada DOT has expanded the RWIS system to 18 sites. Eventually, they plan to have 28 weather stations along the Sierra Nevada range, covering the Lake Tahoe basin and the major routes leading into it.

"This approach to winter maintenance operations provides significant savings and benefits for the DOT and the taxpayer," says Nelson.

  • Over the next 25 years, $7 million will be saved as a result of the reduction in chemicals used, more efficient scheduling of crews, and less damage to vegetation.
  • Environmental quality is improved, with the reduction in the use of chemicals and abrasives.
  • Winter travelers will have more reliable, safer access to the region.
  • Operators of the recreational areas will benefit, as visitors anticipate easier, safer traveling to the resorts.

For More Information

Rick Nelson, Nevada DOT, 702-688-1250 (fax: 702-688-1189; email: h2201rjn@ndot.state.nv.us)
Paul Pisano, FHWA, 202-366-1301 (fax: 202-366-8712; email: paul.pisano@fhwa.dot.gov)

Publication No.: FHWA-SA-96-045 (CS004)

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