The TIF will extend along the elevated tracks from North Avenue to Devon Avenue, a tract more than 6 miles long. In a mile-wide corridor along that stretch of prime North Side property, much of the growth in real estate taxes between now and 2051 would go toward financing the CTA project.

Emanuel and aides hailed the council action as a crucial step to preserve good access to nearly 600,000 downtown jobs.

The central area is "an incredible economic engine," and rush-hour ridership on the Red, Brown and Purple lines that serve it has grown 40 percent in the past decade, said Finance Committee Chairman Ald. Edward Burke, 14th. But trains are crowded, and the tracks and some of the stations are as much as 108 years old, he said.

"This is something we should be proud of," Emanuel told aldermen immediately after the vote. "This is an essential step."

Emanuel was careful to note that while the area involved is entirely on the North Side, the city spent $425 million in 2013 rebuilding the Red Line south and has begun engineering a $1 billion, 5-mile extension of the Red Line from its terminal at 95th Street to the city limits at 130th Street. "All different parts of the city are coming together."

CRITICS ONBOARD

Even longtime council TIF critics seemed convinced.

For instance, Ald. Rick Munoz, 22nd, said he only opposes "speculative TIFs," not project-specific ones like this.

Ald. Scott Waguespack, 32nd, said public transit "has to be subsidized by government" and Chicago has few other options to pay for the project.

Waguespack added he's been assured revenue from the TIF will go strictly to the CTA and not to incentivize private development near the line. "I wouldn't call (supporting the TIF) a conversion at all," he said. "I'd call it a compromise."

Ald. Joe Moore, 49th, noted that, unlike most TIF districts, this one will not shift money from Chicago Public Schools, even temporarily. Under terms of a special state law authorizing the transit TIF, CPS will fully and immediately gain from any growth in property values within the district.

APPROVAL PENDING

The city hopes to hear soon on the federal grant request. Given Emanuel's connections as Obama's former chief staff, and the fact that CTA President Dorval Carter once was a ranking federal transit official, approval is likely.

But it's not certain, Washington insiders tell me.

Either way, with federal and state transit funding sharply limited, the Red Line project would be the wave of the future. Expect more and more CTA projects—including the Red Line south extension and the second phase of the Red Line north work—to rely heavily on local funding sources.

Money for this project will go to build a flyover bridge at the Clark Junction just north of Belmont Avenue, so that Red Line and Brown Line trains do not have to stop for each other, allowing the CTA to add service during rush periods. (Purple Line trains also use the Red Line tracks, but only during rush hours.)

Other portions of the $2.1 billion Phase One will go to install modern signal equipment from Belmont to Howard Street; rebuild the Lawrence, Argyle, Berwyn and Bryn Mawr stations to modern standards; and replace 1.3 miles of old track and embankment from just north of the Wilson stop to Bryn Mawr.