The notorious Crosstown Commons, where a wicked weave of lanes from two highways funneled traffic into one of the worst bottlenecks in the nation, is gone.

The new 35W-Crosstown junction -- an eye-popping 14 lanes across at its widest -- is expected to cut 10 to 20 minutes off hundreds of thousands of trips a day to downtown Minneapolis, the airport, Mall of America, and the south and west suburbs.

The $288 million interchange is the most expensive road project in Minnesota history. Its Cadillac design has peeled the two highways apart with roomy lanes, ample shoulders, 26 bridges and artistic touches on noise walls and lights.

For motorists the frustrating rush-hour delays on I-35W coming south from downtown Minneapolis or north from the Minnesota River are gone.

From the west, the trying one-lane funnel for eastbound Hwy. 62 traffic heading downtown or to the airport is gone.

From the east, the nerve-wracking two-lane-change shuffle for westbound Crosstown motorists who only wanted to keep going straight is gone.

It's the result of major political jostling years ago, when suburban legislators stopped the project until they prevailed in their demands for a bigger design.

With the state's recent shift to a "low-cost, high-benefit" philosophy toward road improvements, the interchange de-tangling is likely the last big-scale project of its kind.MnDOT praised for a change

As final stretches of the four-year project have opened in recent weeks, commuters who aren't shy about complaining about traffic have raved about the time savings and stress relief.

"The way they have unwoven it is great," said Liz Lynch of Richfield. "The flow is just so much better."

John Breitinger of Minneapolis said: "They have clearly fixed a huge problem and created a good alternative for the buses. The real benefit is the reduction of stress."

Traffic flow will be further aided in two weeks with the opening of express lanes for buses and MnPASS users.

What made the old commons so hellish was its intertwining of a major interstate with a dated four-lane highway, made worse by its passage through a giant S-curve.

Now, with the two highways separated, drivers choose either 35W or 62 before entering the interchange.

"You are not allowed to weave anymore," said John Griffith, west area manager of the Minnesota Department of Transportation (MnDOT).

He called it perhaps the last "full-build" project the metro area will see in terms of meeting design standards. "We followed the cookbook in terms of geometry and everything else," he said.

The big project waited years for funding because of its cost, nearly equal to MnDOT's metro district annual construction budget, said Khani Sahebjam, MnDOT's deputy commissioner. To get it rolling in 2007, MnDOT borrowed $50 million from the Metropolitan Council.

Now, to stretch funding, the department looks for ways to relieve congestion and improve safety with "low-cost high-benefit" projects that cost less than full reconstruction, said Tom O'Keefe, MnDOT's director of program delivery.

The grip of the old commons at rush hour slowed traffic in all directions.

"It would back up all the way into Edina a lot of evenings," Lynch said. "Everyone was jockeying and you were irritated." Some drivers would race to the head of the line and squeeze in. "That made everybody try to get bumper to bumper."

After a decade of design and redesign, the interchange was rebuilt in four years in a massive theatre of construction by Lunda Construction of Black River Falls, Wis., Ames Construction, Inc., Burnsville, and Shafer Contracting of Shafer.

The broad scale of operations made it "more stressful and more difficult for everybody involved," said MnDOT project manager Steve Barrett. Despite the four years it took, he said "it was a very fast-paced project" under pressure to stay on schedule.

During project peak in 2008 and 2009, MnDOT had 25 inspectors working day and night to inspect grading, paving and bridges.

"One of the things that we struggled with, and everybody was frustrated with on all sides, was the close proximity of this project to the neighboring homes," Barrett said. Residents suffered through dust, vibration, noisy nights and water and sewer disruptions.

"I'm so glad it's over," said Barb Lewis of south Minneapolis. "I didn't open a window for two years" to keep out "the dirt from the trucks and the exhaust fumes." Whenever 35W was closed for construction, traffic was bumper to bumper in front of her home on Nicollet Avenue.

How the old became new

Drivers were buffeted by constantly shifting lanes with some counter-intuitive traffic switches. One involved the Crosstown exits from southbound 35W that, for a time, fooled some people into heading west to Edina instead of east to the airport.

Many commuters said they were surprised at how well traffic kept moving during construction.

"It really did not affect my commute time that much," said Elizabeth Whitacre of Lakeville. "I thought it was brilliant, really."

To stay out of motorists' way, contractors started outside the old road with widening and bridge building. Then all traffic was pushed first to one side and then the other to build the new lanes, Barrett said.

Recycled bits of the old Crosstown pavement went into the gravel bed under the new lanes, said Shafer President George Mattson.

"Our work is what you drive on out there, and we are kind of proud of it," Mattson said. "The concrete will last maybe 50 to 60 years without needing much work on it."

Nightmare delays, then a fix

The one-mile common section was built in the 1960s after plans for a standard cloverleaf were scrapped under political pressure to reduce the taking of land and houses in Richfield and Minneapolis.

As traffic volumes grew, so did delays. In 2000, the American Automobile Association named it to a national nightmare list of freeway bottlenecks. The commons section was congested 14 hours a day, with an accident rate 50 percent above any other stretch of metro freeway.

Despite wide agreement to fix it, there were sharp differences about how to do it. Minneapolis wanted transit improvements instead of more lanes. South and west suburbs wanted more lanes.

MnDOT's first design kept the freeway in its original footprint, improving safety but adding little capacity to ease congestion. Minneapolis liked it. Critics protested that, like the old commons, it had just a single lane connecting eastbound Crosstown to north 35W.

After learning that the limited rebuild would close parts of the Crosstown for up to three years, suburban legislators led by then Sen. Roy Terwilliger, R-Edina, stopped the project and sent MnDOT back to the drawing board. The second try -- with two lanes connecting eastbound Crosstown to north I-35W -- carried the day.

"It has made a humongous difference as that traffic comes together there," Terwilliger said. "There are things that, as you look back, you are pleased that you were involved with. This is one of those things."

Minneapolis Mayor R.T. Rybak said the city's unwavering insistence that the Crosstown advance transit also was critical to the design's success, and finally put buses in position to "help solve our congestion problems."

Transit-toll lanes on 35W through Richfield were added all the way to downtown Minneapolis. Those new lanes figure into the plan for so-called bus rapid transit, or BRT, between Minneapolis and Lakeville starting in late 2012. The transit push also led to rebuilding Marquette and Second avenues to speed buses in and out of downtown Minneapolis.

"We are now going to be able to take one of the biggest pains in the neck at rush hour and turn it into a relatively pleasant drive," Rybak said.

Congestion move or go away?

Unclogging the Crosstown bottleneck may cause congestion to show up in other places people haven't seen before, O'Keefe said. But Richfield Public Works Director Mike Eastling said he expects wide-rippling benefits from vastly improved east-west movement through the new interchange.

"It's going to be a real noticeable change in the region," he said.

Laurie Blake • 612-673-1711