Downtown Minneapolis will be teeming with year-round street life, criss-crossed by transit lines and a web of commercial and residential activity by 2020, Mayor R.T. Rybak told the city’s business leaders Wednesday.

In his last appearance at the Downtown Council’s annual meeting as mayor, Rybak outlined a bold vision of changes to sustain the goal of doubling downtown’s population.

The plan relies on installing streetcars, reimagining Nicollet Mall and Hennepin Ave., improving retail options and developing around the new Vikings stadium, Rybak said.

The most unusual idea? Using steam from the Hennepin County garbage burner to heat sidewalks and more on Nicollet Mall.

“We may be able to grow palm trees on Nicollet Mall with all that wonderful steam that now goes up into the air,” Rybak said, seemingly in jest. He also proposed better connections between the streets and skyways to improve street-level activity.

Several times during his 12-minute speech, the outgoing mayor highlighted the need for streetcars to complement the handful of light rail lines he expects will eventually run through Minneapolis. He said while the downtown population will double, there should be no additional cars on the street.

Conceding that “not everybody in this room is on board with the idea of the streetcar yet,” Rybak emphasized that, “If we do not build a streetcar in this town, we will be transit gridlocked.”

As for a redo of Nicollet Mall, Rybak said that financing and design plans will be in place by the end of the year.

"It’s now time to do Nicollet Mall 3.0,” Rybak said. “And Nicollet Mall may not even be called Nicollet Mall anymore. It will be Nicollet whatever, but it will be a great street.”

Turning to what may have been his greatest political risk as mayor, Rybak said it is imperative that the new Vikings stadium not be surrounded by parking lots like its peers across the country. He said the area should instead be peppered with corporate campuses, housing and linkages to the downtown core through places like the Star Tribune land.

“We’re going to see that football stadium connected with what we committed to,” Rybak said. “We’re going to surround it with development.”

The downtown of the future will also be a more interconnected blend of residential and commercial uses, he envisioned. “We’ll erase that imaginary line between where we live and where we work,” Rybak said.

The mayor noted that retail will also play an important role in making the downtown of 2020 an attractive place. Better “retail management” is needed, he said, because “we have not figured out how to do retail right.”