Nate McCormick and his colleagues spend a lot of time on the road roasting pigs at events around the metro, so they've noticed it's been a rough construction season already.

But this week, it's all coming home. An already congested bridge that leads to their restaurant in Shakopee is about to be squeezed down to half its width for weeks.

"It will definitely hurt," he said. "You're not going to have random people just passing by."

At least it won't be as bad as for Deb Irvin, a little ways north on Hwy. 169. She at times will lose an entire off-ramp from a major highway leading to her coffee shop in Bloomington.

"It's already a mess," she laments. "It's about to get brutal."

The scale of disruption from the work that begins Friday night on the Bloomington Ferry Bridge is so immense that the Minnesota Department of Transportation has been presenting PowerPoint talks at local gatherings at least since January, dodging snowflakes to warn of what's in store for the south metro in the withering heat of late summer.

Long lines of cars headed from Savage toward northbound Hwy. 169 and the Bloomington Ferry Bridge last week. MnDOT work is about to make things much worse.

For three weeks, the bridge and some of the highway to the north will be undergoing repairs. They are major arteries for commuters and also bring folks to a bunch of summer entertainment attractions such as Valleyfair.

If the project threatens to disrupt the opening weekend of the Renaissance Festival, said spokeswoman Deb Schaber, "we would probably send everyone to [Hwy.] 212 and then to 41, where we have an entrance as well as from 169. But we understand there are hefty incentives to be done early, is what we're being told. So it might not affect us. But there's Mystic Lake [Casino], there's Canterbury — there's a lot of things."

In recent days, the state has been able to be more specific about the details, which in some cases vary from what had been said before.

Single-lane, head-to-head traffic in both directions of Hwy. 169 between Shakopee and Bloomington will begin at 10 p.m. Friday, in hopes of missing the highest periods of use.

"Both directions of traffic between Old Shakopee Road and Hwy. 101 will be shifted to the north side of the road,'' said Kirsten Klein, spokeswoman for the department's metropolitan district. And these ramps to and from 169 will close: Pioneer Trail, Old Shakopee Road, Hwy. 101 and County Road 21.

Signage will be out suggesting detours for the ramp closures, she said, and officials are suggesting alternate routes across the river, such as Hwys. 101, 41 or Interstate 35W.

That suggests that the work on Hwy. 169 will impact a wide area indeed, in some cases roadways that are hardly free-flowing to start with.

Work on the southbound lanes is expected to take about two weeks. Traffic then will shift to the southbound lanes as work begins on the northbound side.

The $5.45 million project aims to replace joints on the Bloomington Ferry Bridge and do other work on Hwy. 169 from Hwy. 101 in Scott County to Pioneer Trail in Bloomington and Eden Prairie.

Some of the work will strengthen the shoulders to make them better able to handle the stress when the road is restriped to add a lane. That occurs when flooding closes other less floodproof river crossings. The work is also preparing for impacts from future projects on the Hwy. 101 bridge in Shakopee, which will mean diverted traffic.

How many drivers will be affected? Last year, the state's counts show, daily southbound traffic on Hwy. 169 over the Minnesota River peaked at around 50,000 vehicles on weekdays during the summer.

And partly because of all the attractions, weekend traffic wasn't always massively less heavy. It did at times dip below 40,000, but as the Renaissance Festival and other events geared up in late August and September, weekend traffic was nearly the same as weekdays.

The potential impact on the Scott County side is hard to gauge. If it keeps south-metro residents closer to home in quest of meals and the like, or reroutes more traffic west to Hwy. 101, it could actually help a business like McCormick's Mr. Pig Stuff, in its new quarters on the eastern edge of Shakopee along 101.

But it feels like some quiet days are approaching for businesses such as Irvin's West Side Perk coffee shop, along Old Shakopee Road in Bloomington, just east of the highway.

Scott County officials just got done compiling statistics for population and employment along Hwy. 169, for purposes of lobbying for the location of rapid busway stations. So the magnitude of the effects isn't hard to find:

• At Old Shakopee Road, for instance, in 2010, about 35,000 people lived within a two-mile radius, while nearly 10,000 people had jobs within that same radius.

• At Canterbury Road (County Road 83) in Shakopee, the comparable numbers were about 31,000 population in 2010 and about 12,000 jobs.

The bridge was built in 1993, and the life cycle for joints is 20 years. Officials have pictures that indicate substantial deterioration, with salt and water reaching the substructure and attacking it.

The end date is being expressed as just "late August," and things can always change.

David Peterson • 952-746-3285