A few Drive readers have spotted brown fences being installed at two interchanges along Hwy. 10 in the north metro. They have also noticed the fences are well off the road and don't appear to be a barrier to stop or slow vehicles.

"Can you tell me what these fences are for?" Drive reader David asked in an e-mail after he saw one of the new fences at Hwy. 10 and Main Street in Anoka.

It's sweltering hot now, but the Minnesota Department of Transportation is preparing for winter by building snow fences to reduce the amount of snow drifting onto ramps and roads, spokesman Kent Barnard said.

"Blowing snow events can happen with wind speeds greater than 13 mph with snow on the ground," Barnard said. Fences break up the wind pattern and "the idea is to keep snow from going over the roadway and freezing and creating icy conditions."

A series of 4-foot fences — 812 feet altogether — are going up on the northeast quadrant of Hwy. 10 and Main Street. At Hwy. 10 and Round Lake Boulevard in Coon Rapids, MnDOT is installing fences on the southwest and northeast quadrants and planting a "living snow fence" with three rows of hybrid willow shrubs to trap snow near the ground when winds blow. The fences will cost $156,000.

One of the first snow fences appeared about 15 years ago at the I-494/694/94 interchange in Maple Grove "where there was a real problem" with drifting, Barnard said.

The Kern Bridge, one of the oldest bridges in Minnesota and made from wrought iron, is up for sale.

Since then, MnDOT has put in both structural and living snow fences at a handful of interchanges in the metro that are prone to drifting, including I-494 at Tamarack Road in Woodbury, I-694 at Century Avenue in Oakdale and along Hwy. 169 in Shakopee. Two more are planned, at Hwy. 212 and Engler Boulevard in Chaska and at Hwy. 7 and County Road 10 near Waconia.

"Fences save money and save lives by keeping roads clear and traffic moving [in winter]," Barnard said. "To see them work their magic, you will have to wait a few more months."

Many Drive readers are probably very happy to wait.

Historic bridge for sale

MnDOT wants to sell you a bridge. Really.

The agency is looking for somebody to buy the historic Kern Bridge, which is the only bowstring arch bridge in Minnesota and, at 189 feet, is the longest of its type in the nation and second longest in North America.

MnDOT is accepting letters of interest from potential buyers through Aug. 31 with final applications due Sept. 30.

Made from wrought iron, a rare type of bridge material, the 147-year-old bridge spanned the Le Sueur River southwest of Mankato, Minn., and was initially used for horse and buggy traffic. It closed to pedestrians and vehicles in the early 1990s. MnDOT teamed with Blue Earth County to save the bridge, which was dismantled earlier this year and placed in sealed containers to preserve it.

"The Kern Bridge would be an attractive addition to a bike and pedestrian trail," said Katie Haun Schuring, MnDOT historian. "While our main goal is to see the bridge reused and for many people to experience this unique structure, it would be ideal if the bridge could be in a similar setting to its historic one, over water."

The cost of buying, rehabilitating and relisting Bridge L5669 on the National Register of Historic Places is estimated at $1.5 million. Federal funds covering 80% of the cost are available, MnDOT said.

Follow news about traffic and commuting at The Drive on startribune.com. Got traffic or transportation questions, or story ideas? E-mail drive@startribune.com, tweet @stribdrive or call Tim Harlow at 612-673-7768.