On summer days, Nicollet Mall might seem like a study in urban vibrancy, with diners gathering at sidewalk cafes, farmers selling the spoils of the earth and harried office workers scurrying about.

But Minneapolis' commercial spine has aged considerably since its last face-lift nearly a quarter-century ago, with cracked and leaky sidewalks, dated lighting fixtures, occasional barren blocks, and commuter-unfriendly bus shelters. To remedy the mall's physical ills and craft a broad strategy for the boulevard — from Grant Street to Washington Av. — the city sponsored an architectural design competition, and preliminary results are in.

Twenty-one design teams submitted proposals, and three emerged as finalists whose proposals will be presented to the public at 5 p.m. Sept. 17 at the Guthrie Theater. The Minneapolis City Council ultimately will make the choice, triggering a dialogue between the winning team and the public.

"We not only have to fix Nicollet Mall's structure, we have to reassert Nicollet Mall as a great American Main Street," Mayor R.T. Rybak said last week.

A pressing question is who will pay for the project, which has a price tag of $30 million to $40 million. The city envisions a $20 million contribution through a state bonding bill, with private businesses ponying up the rest through a still-undefined assessment fee. Two Fortune 500 companies headquartered on the mall, Target Corp. and U.S. Bank, declined to comment on the rehab or couldn't be reached regarding the project.

But Rybak points out that local businesses came to the city with concerns about the mall's deteriorating state, and the Downtown Council is a partner on the design competition and has championed the overhaul in its 2025 Plan, a blueprint for the city core.

Rybak admitted that the ideas and images generated in the contest will help champion his cause at the Capitol. The renderings do provide an interesting, if preliminary, peek at ideas for the 12-block strip. All appear to embrace more trees and landscaping, as well as additional pockets of pedestrian seating.

"You have a beautiful street that is beautifully framed at the city's center," said Renée Daoust, of Montreal-based Daoust Lestage, one of the finalists. "But it's interesting, if you look at an aerial photograph of Minneapolis' downtown, it's devoid of trees, except for the Mississippi River and Loring Park. You really need to optimize the landscape."

Pedigreed firms

All three finalists, including James Corner Field Operations of New York and Tom Leader Studio of Berkeley, Calif., have international reputations, and some have partnered with local firms as sub-consultants. Each will receive a $30,000 stipend from the city to complete the designs.

British-born James Corner, for example, has won wide acclaim for his firm's redesign of the High Line public park in Manhattan, which was built on an elevated rail-line bed. His firm is slated to tackle a renovation of Chicago's Navy Pier.

Leader's firm was involved in the design of the $175 million RiverFirst development along the Mississippi River, north of downtown. "That's how we got to know the area, and then we opened an office [in Minneapolis]," Leader said. "When we heard about the mall project, we thought it would be a great way to link the river and downtown together into an integrated system of spaces that are both naturalized and very urban."

Leader said his firm's design of a major pedestrian corridor at Stanford University's Medical School is similar to the Nicollet Mall project. "It really is the lifeblood of the campus there," he said.

Nicollet Mall is architecturally significant in its own right. Although it has served as the city's retail thoroughfare since the 1880s, the pedestrian-transit mall concept came about as downtowns withered in the 1960s' suburban shopping-mall boom, a trend pioneered by Edina's Southdale.

Influential landscape architect Lawrence Halprin in 1962 designed Nicollet's signature serpentine curve, although he also added fountains, street furniture, landscaping, public art and heated sidewalks (later abandoned).

No facade changes — yet

The planned overhaul will not include any of the business facades lining the mall, which range from architecturally significant (Philip Johnson's IDS Center), to early 20th-century (the Macy's department store), to bunkerlike (City Center). Nor will it involve Peavey Plaza, which is slated for a separate face-lift.

City officials hope that a renovation of the mall will spur businesses to spruce up their buildings and encourage occupancy in several prominent, vacant retail spaces.

"We felt that investment in the public space could serve as a catalyst," said Ben Hecker, interagency coordinator at the city's Public Works Department. "We really want to encourage street-level activity."

The designs will incorporate various modes of transit — buses, taxis, bicycles and perhaps streetcars. The City Council in June approved a plan to redirect up to $60 million to help pay for a streetcar line running along Nicollet and Central avenues.

In the past year, the mall has changed as deep-pocketed national firms bought several signature buildings, including City Center, Gaviidae I and II and the former Neiman Marcus store. When California-based KBS Real Estate Investment Trust III closed on its purchase of Gaviidae II and RBC Plaza for $118 million in February, it announced that it would pump nearly $4 million into the shopping center and office tower. However, it's still unclear how these ownership changes will affect the mall's real estate.

The mall soon will have an influx of new upscale residents as Opus Development Corp. builds a $100 million luxury apartment tower at Fifth St. S. and Nicollet Mall, kitty-corner from a 30-story residential tower being constructed by Mortenson Development along Marquette Av.

The two projects will mean hundreds of new residents will be able to live on or near the mall, beyond the 36,000 people who already call downtown Minneapolis their home.