The flashing marquees, noisy bars and gritty sidewalks of Hennepin Avenue have inspired and intimidated generations of visitors and locals in downtown Minneapolis.

Starting Monday, the Hennepin theater strip will turn into a four-year construction zone, diverting buses, choking traffic and disrupting businesses from 12th Street S. to Washington Avenue. The $23 million reconstruction is the largest project of its kind since Nicollet Mall went through its own makeover earlier this decade.

By the time construction wraps up in 2022, the new Hennepin Avenue will have wider sidewalks, trees, protected bike lanes, upgraded utilities and brighter streetlights. Mark Nerenhausen, president of the Hennepin Theatre Trust, has high hopes for what’s changing on the strip.

“This isn’t just about putting down new concrete,” said Nerenhausen, whose organization operates three historic theaters there. “It’s really about, in a sense, renewing a hundred-year-old theater district.”

The work won’t happen all at once. The first two years of construction will take place between 12th Street and 7th Street. Crews will then shift over from 7th Street to Washington Avenue sometime in 2021.

Last rebuilt in 1986, Hennepin Avenue offers a confluence of entertainment, dining, nightlife and street life that’s unique in the Twin Cities, where people can go to catch both a touring Broadway show and a local bus to St. Paul.

Visitors come from all over to see plays and musicals at the Pantages, the Orpheum, the State and more. Twins and Timberwolves fans cross the street to get to the stadiums or watch at bars. Concertgoers take smoke breaks outside of the Skyway Theatre.

Don Elwood, the city’s director of transportation engineering and design who is leading the reconstruction project, said the beauty of Hennepin Avenue lies in its constantly rotating identity.

“Some people don’t like that — I do,” he said. “Hennepin changes during the day and the day of the week.”

That churn of activity has worn out the street both above and underground. A 19th-century sewer system is crumbling. On the surface, cyclists are pressed up right along vehicles. Pedestrians have to cross five lanes of cars.

Underground work first

This year, most construction will take place underground. Crews will dig more than 20 feet down to replace sewer and water lines and work on other utilities. During this time, the road will be reduced to one-lane traffic in each direction, with no left turns allowed at intersections.

The most dramatic change will happen with the Metro Transit bus routes. Buses will avoid the stretch from 12th Street to Washington Avenue entirely for four years, and will instead pick up and drop off passengers on Nicollet Mall.

Steve Cramer, president of the Minneapolis Downtown Council, was worried about what that added congestion could mean for Nicollet Mall.

“The only worse thing than doing this project is not doing it,” he said. “If we ignore these investments in our city … then the longer-term consequence of that is even greater.”

Nerenhausen hopes the changes will make for a “safe, vibrant and attractive theater district.” That goes for other venues on the street, too, including Brave New Workshop, an improv comedy company that has performed on Hennepin Avenue since 1958.

Tom Reed, who acts, writes and teaches for the theater, commutes by bike but tries to avoid Hennepin Avenue, especially after he was hit by cars further down the road by Uptown.

He notices the street has become more bustling over the five years he has worked downtown. While it’s not Manhattan, it’s as close to the big-city feel as Minneapolis can get, he said.

“It kind of marks time,” Reed said. “Are people wearing cowboy boots? Oh, there must be a country music concert at Target Center. Are people wearing Twins hats? Twins game is today.”

While supportive of the upgrades, some business owners are wondering how they’re going to get through the next four years.

Tiffany Blackwell, the owner of the V.I.P. Hair & Nails salon on 12th Street, is concerned that construction will keep people away from Hennepin Avenue and make it difficult for some of her customers to get to the salon.

“It creates such an inconvenience for everyone,” she said. “I guess we just have to take it one day at a time.”

In the 16 years she has worked on Hennepin Avenue, Blackwell has learned to live with both the good and the bad of the strip. While it’s a prime location for business, she acknowledges she hasn’t always felt safe walking on the street.

Panhandling, street harassment and drunken fights led the city to increase patrols by police officers and ambassadors from the Minneapolis Downtown Improvement District. In the future, Elwood hopes the wider sidewalks and new lighting will also help make for a better pedestrian experience.

Elwood and the city’s public works department are holding regular meetings to keep business owners on the street up to date. While there are a lot of unknowns as the city embarks upon the multiyear project, more will become apparent once crews break open the road on Monday.

“You don’t always know what’s under the pavement when you open it up,” Elwood said.