Mayor Rahm Emanuel, CTA President Forrest Claypool and CTA board chairman Terry Peterson tour the 47th Street Red Line Station concerning the Red Line South reconstruction project in Chicago on July 2, 2013. (Zbigniew Bzdak, Chicago Tribune)

CTA officials say the Red Line reconstruction is on budget and on schedule to be done by October, but they had little information Tuesday about the cost of special CTA service or how ridership has been affected by shutting down the southern part of the city's busiest public transportation route for more than a month so far.

The update came as Mayor Rahm Emanuel joined CTA President Forrest Claypool and board Chairman Terry Peterson for a photo-op stroll along the gravel path where until recently the Red Line tracks ran under 47th Street in the middle of the Dan Ryan Expressway.

The mayor predicted businesses will want to set up shop near the line when the work is complete. "It also means, because of the traffic, there will be more retail opportunities," Emanuel said.

After the mayor left, Claypool told reporters the $425 million Red Line reconstruction that started in May between the Cermak/Chinatown and 95th Street stations should be completed by October.

To curb the inevitable inconvenience to riders as part of the politically sensitive project, the agency added free shuttle buses from the closed Red Line corridor to the Garfield station on the Green Line, where riders can board for free.

Bus rides are also being discounted 50 cents for routes south of 63rd Street. The CTA hired additional bus drivers, in part to handle the shuttle service and added bus passengers on South Side routes.

The cost of providing the extra and alternative service is estimated to run $13 million by the time the project is complete. But Claypool said he doesn't know how much money has been spent so far on the beefed up South Side bus service.

"We are tweaking service on a weekly basis to address ridership patterns, so we won't know actual cost until project completion," CTA spokesman Brian Steele said in an email.

Emanuel has pitched the work to the predominantly African-American ridership on that part of the Red Line as the fastest, most cost-efficient way to replace the aging track and speed the trip downtown by up to 20 minutes.

Claypool said it's too early for the CTA to tell whether ridership has fallen significantly during the six weeks the Red Line has been closed, as it did during the two-year Green Line reconstruction during the 1990s. Early on in the Red Line work, Claypool said ridership was "down a little, as expected."

The CTA tracks ridership on a daily basis and the agency produces monthly ridership reports, which have not been updated on the CTA website since April. CTA officials use the ridership data internally to decide where to add and reduce service, whether it's the Red Line south project or the recent temporary shutdown of the Wells Street bridge downtown.

"Can't say for sure. From what we can tell, obviously a lot of people are using the shuttle service," Claypool said. "We also have seen heavy ridership growth on the bus lines that parallel the Red Line, which is not surprising. We've actually added a lot of service in response to that."

Tribune reporter Jon Hilkevitch contributed.

jebyrne@tribune.com

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