If you see a 1,200-gallon water tank traveling down the freeway at a weird angle in the middle of a snowstorm, don't be alarmed. It's just a new kind of snowplow.

Called a tow plow, it's attached to a trailer and is pulled behind a regular snowplow. Combined with the blade on the front of the truck, it allows drivers from the Minnesota Department of Transportation to clear more than two lanes of freeway at once.

MnDOT says its five tow plows, which cost $60,000 apiece, save fuel and reduce wear and tear on vehicles, equipment and humans. Minnesota is the first state in the Upper Midwest to use them, the agency says.

Such plows are so complicated that the trucks pulling them are equipped with automatic transmissions, so the driver's right hand is free to deal with the vast array of buttons, switches and levers.

One of the buttons turns on a laser beam, which projects a green dot ahead of the truck toward the right shoulder to help drivers determine how far they need to be from guardrails. A camera mounted on the passenger-side rear-view mirror is connected to a 7-inch screen inside the cab to give drivers a better view of the 26-foot-long blade.

The wheels on the trailer pivot to allow for the unusual angle of travel, while the water tank serves as ballast -- the weight that keeps the plow from being pushed back by the snow. It's filled with a corn salt solution that won't freeze, and at some point, MnDOT hopes to use the tank for anti-icing fluids.

About a year ago, Terri Schreifels and other workers at MnDOT's Maple Grove truck station were skeptical that the Canadian-built tow plows would work, but the crew was soon converted. As Schreifels plowed parts of Interstates 494 and 694 during Thursday afternoon's snowstorm, he kept the speedometer at around 25 miles per hour -- any faster than that, he said, and the "snow cloud" would make it too hard to see.

The tow plows are equipped with a dazzling array of yellow, blue and red lights to make them visible to motorists and give drivers time to slow down and stay back. But even all that wasn't enough to deter a small black car from darting between Schreifels' rig and the lead plow ahead of him. New technology, it seems, can do only so much.

Mark Boswell contributed to this report. Jim Foti • 612-673-4491