Amid an avalanche of criticism from motorists, the Minnesota Department of Transportation is standing by its decision to shut down Interstate 35W between downtown Minneapolis and Crosstown Hwy. 62 this weekend even though three major sporting events are happening in downtown Sunday.

Even Gov. Mark Dayton expressed "serious concerns" about the potential traffic disruption. He called State Transportation Director Charlie Zelle and directed MnDOT to ensure that alternate route accommodations they have arranged are communicated clearly to event organizers and the public.

More than 100,000 people are expected to take in the Twin Cities Marathon, a Vikings game and a Twins game, all on Sunday. And anybody coming from the south metro will have to find another route because the main artery into downtown will be closed from 10 p.m. Friday until 5 a.m. Monday. Other weekend events include a Gophers football game Saturday and Twins games both Friday and Saturday nights.

The decision to shut down I-35W on a such a heavy sports weekend has drivers scratching their heads and asking why the closure could not have been pushed off another week when the events calendar will be much lighter.

"If the work was scheduled for next weekend, the Twins season would have been over and the Marathon would have been run," Tom Carlson of New Brighton wrote in an e-mail to the Star Tribune. "And there would probably be 80,000 less people downtown." The Vikings also are on the road.

In a statement Wednesday, Zelle said his agency has worked with the Vikings, Twins, marathon organizers as well as the U "so they have time to alert their patrons about the closure."

"The redesign of the I-35W corridor through Minneapolis is a very complex project, and the work we accomplish this weekend is necessary to keep it on schedule and any delay would add significant costs to the project," he said.

MnDOT is closing the freeway between Crosstown and Interstate 94 to move utilities before it demolishes the Franklin Avenue bridge the following weekend. It's all part of a sequence of construction tasks related to the $240 million I-35W redo that must be completed this fall, said West Metro District Engineer Scott McBride. Pushing back the closure by a week would affect other work "that is stacked up like dominoes. If one thing does not happen, it will affect everything down the road."

Over the weekend MnDOT will be relocating water main lines and sanitary systems, work that needs a chunk of time and could not be completed with a series of overnight closures. MnDOT also needs good weather when digging underground, something the weekend will offer, McBride said.

McBride pointed out that planning for rebuilding I-35W from 46th Street to I-94 has been ongoing for six to eight years and that the closure was timed around finishing other major construction projects, including adding a third lane on I-494 through Plymouth and Maple Grove and expanding Hwy. 100 through St. Louis Park the past two years. It also comes after the bulk of the work on I-94 between Brooklyn Center and downtown Minneapolis was completed this summer. MnDOT also waited until the new Nine Mile Creek bridge on Hwy. 169 in Edina was finished.

"That is the thinking we do that people don't see," McBride said. "People think we intentionally set things up to make lives miserable. I wish people could see the decisions we make to save them headaches."

McBride said MnDOT looked at Sunday's events and noted that start times were staggered and that not all people attending them would be coming from the same direction. If all the events had the same start time, "the decision might have been different."

MnDOT has the authority to make the call when it comes to shutting down roads, but does alert the governor's office when there are sensitive closures. Word about this weekend's closure was delivered to the governor on Wednesday morning.

Virginia Brophy Achman, executive director Twin Cities In Motion, the organization putting on Sunday's marathon, said she was well aware of the closing, and MnDOT agreed to post signage at Friday and Saturday's Health & Fitness Expo to remind runners.

"We're confident runners are learning about the situation, and we will be reminding them through race morning," she said.

Tim Harlow • 612-673-7768