Drivers in Soldotna may have thought they were behind a jack-knifed truck and trailer, but the big rig taking up two lanes of highway was actually the state's latest piece of snow-clearing equipment.
The Department of Transportation and Public Facilities deployed one of Alaska's two new "tow plows" for the first time on Friday morning. It makes it possible for one snowplow truck clear twice as much road in a single pass.
The plow is a double-axel trailer with a blade that can be steered from the cab of the regular plow truck to which it's attached. The truck's blade clears 11 feet on the left side of a road while the trailer is angled out 30 degrees and it's blade lowered to clear 13 feet on the right side.
Some drivers might be alarmed by the sight the first time they encounter it, said Michael Coffey, statewide maintenance engineer for the department. "We want to make sure that drivers aren't caught off-guard and understand that the plow is working as intended."
The plows were introduced in the Lower 48 in 2005, first in Missiouri. So far, 17 states are using them, as are Canadian road maintenance crews. California acquired one to clear the treacherous Donner Summit route earlier this month, according to news reports.
A report from the Maine Department of Transportation gave an enthusiastic evaluation of the plows, which were used both on interstate routes and local highways beset by steep hills and heavy, wet snow. During the 2009-10 season the state's Viking-Cives Tow Plows pulled by Volvo Wheeler trucks were "unable to crest hills" four times -- twice because a tractor trailer had stopped in front of them, the report said. "In each instance, the driver was able to back down and accelerate up and over the hill."
There are financial benefits associated with the plows. They cost less than trucks, require fewer man hours compared to running two trucks in a staggered configuration and use an estimated 30 percent less fuel than two trucks.
"The savings are great," said ADOT&PF's Jeremy Woodrow in a phone call from Juneau. "But the main thing is that it allows us to dedicate our resources to get to other roads sooner." The second truck that would otherwise be following the first can now be sent to work on secondary roads that have previously had to wait to be cleared.
In addition to the blade, the trailer carries two 1,000 gallon tanks with spray bars. De-icing liquid -- typically salt brine -- can be dispersed. The liquid also serves as ballast. In some states sand or gravel hoppers replace the tanks of de-icer.
The Maine study noted one potential problem area. The plows moved at between 15 and 25 miles an hour "with little opportunity to pull off the road and allow traffic to pass. This often created long lines of disgruntled travelers."
However, Woodrow said, the slowdown isn't any different than being behind a procession of plow trucks. "I think people would rather have a clear road," he said.
As with conventional snowplow trucks, motorists should stay at least 200 feet back of the tow plows and should not attempt to pass on the right. Drivers following too close may find themselves in a white-out under the right snow conditions.
The state has purchased two of the plows at $90,000 each, which included shipping and installation, Woodrow said. They will probably be most effective in places where there are at least two lanes of traffic going one direction, he said.
The one on the Kenai Peninsula will be used in the urban areas like Soldotna and Kenai as well as wider sections of area highways from Sterling to Kalifornsky Beach Road. If all goes well, more may be acquired over time to clear roads in other parts of the state, including parts of the Glenn and Parks highways.
The other tow plow currently in the state is in Juneau and has not yet been used. "It's 40 degrees and raining here," said Woodrow. "We don't know when we'll see a chance to try it out."
Reach Mike Dunham at firstname.lastname@example.org or 257-4332.