The best green light ever arrived Monday for tens of thousands of motorists who stop, go and stop some more through the stoplight jail that is Hwy. 169 at Interstate 494 in the southwest suburbs.

After years of lacking the money, the Minnesota Department of Transportation said Monday it now has the entire $172 million needed to buy land, move utilities and rebuild the critical interchange. Doing so will eventually get rid of the last three sets of stoplights on Hwy. 169.

Construction on Hwy. 169, which handles 75,000 motorists daily on trips through Edina, Eden Prairie and Bloomington, is set to begin next spring and be largely complete by the end of 2012.

The long-awaited project aims to unclog traffic that backs up during six hours of each weekday and often on weekends. The stoplights are the only ones left on what is otherwise a freeway between the Minnesota River and the heart of Hennepin County's suburbs.

Last week a final $34 million fell in place when the Metropolitan Council Transportation Advisory Board directed federal funds set aside for metro area projects to the 169-494 bottleneck. The Met Council is expected to approve its advisory board's decision.

Without that money, the state would have had to wait for another federal stimulus package to get the project going, said John Griffith, MnDOT's west metro area manager. The total sum will come from various state, federal and local sources, he said.

"It's been a long time coming in terms of funding falling into place," Griffith said. "It's always been a priority for us. It's a matter of getting the money we are looking for at the right time."

The road is a key economic thoroughfare connecting communities south of the Minnesota River to the core metro. When spring flooding last week closed river crossings at Shakopee and Chaska, Hwy. 169 became the only way to cross the river between Interstate Hwy. 35W and Jordan.

Eden Prairie Mayor Phil Young said: "Reconstruction of this interchange is absolutely necessary to the economic vitality of the area. This is great news for the city of Eden Prairie and our neighbors in the southwest metro and south of the Minnesota River."

Across the river, Scott County Commissioner Jon Ulrich applauded the project's go-ahead as "great news for Scott County and our region."

To save money, the four-lane Hwy. 169 opened in 1997 with stoplights instead of freeway overpasses at three intersections. But the lights caused safety problems and delays from the outset. Drivers cheered when construction of overpasses removed signals at Pioneer Trail and Bloomington Ferry Road in 2006.

That left delays at the remaining lights at Highwood Drive, south of 494, and on either side of the bridges over 494. MnDOT had a chance to remove them in 1999 when bridges over 494 were deficient and had to be replaced. But lacking the funds to build a signals-free interchange, the department fixed the bridges and replanted the lights.

Now that a new interchange is a go, MnDOT will ask contractors to both design and build it -- a time-saving approach that allows some construction to begin before the entire design is finished.

By July, MnDOT will give competing builders information to start preparing their bids. The winning bid will be selected in November, Griffith said.

Construction would start in spring 2011 and be largely finished by the end of 2012, but some work is likely to continue into 2013, he said.

The chosen builder will be required to keep traffic moving on Hwy. 169 during construction, Griffith said.

MnDOT will rebuild the interchange with just six of the eight expensive fly-over ramps that federal policy requires on such major interchanges. The scaled-back design will save $30 million but MnDOT would have to build the ramps later if they are needed, Griffith said.

Laurie Blake • 612-673-1711