CHICAGO (CBS) — The CTA compares it to open heart surgery: the shutdown of the Wells Street Bridge for reconstruction, starting this weekend – affecting the Brown Line and five other lines. And Mayor Emanuel says the city is saving money – and time.

Mayor Emanuel says it is time to replace the Wells Street Bridge.

“So in nine days, we’re going to replace a bridge that was here for the last 90 years. Warren Harding was president then, and if I can say, not that great a president,” said Emanuel.

Emanuel says the city’s project is efficient.

“We are saving half a million dollars and we’re saving eight days of work. Why? Because what would’ve happened in the past was, CDOT (Chicago Department of Transportation) would’ve done the bridge – and that would’ve slowed everything down or actually shut it off – and then years later, CTA would’ve done the tracks.

“We’re doing the tracks and the bridge simultaneously, saving money and time. So that’s a dramatic example of different and smarter management, in my view,” said Emanuel.

Actually, this is just the first part of the Wells bridge shutdown. The Wells Street Bridge will be closed through March 10. This, to replace the south half of the bridge.

It’s happening again at the end of April – for the north section of the bridge. It will be closed April 26 through May 5.