The severance agreement negotiated between Metra and former CEO Alex Clifford, paying him as much as $740,000 to leave the agency before the end of his contract, pledges both sides to secrecy.

The 14-page agreement includes a "mutual confidentiality" clause in which board members and Clifford agree they will not "disclose the terms or any other circumstance relating to the negotiation of this agreement."

That provision and other terms of the agreement approved Friday by the commuter rail agency have drawn fire from a variety of transportation and legal experts, public officials and customers.

Former state Sen. Susan Garrett, a vigorous Metra critic during her time in office, said Monday that she is unaware of any public agency ever providing a buyout like the one Metra has given Clifford.

"This is a gigantic buyout. It's unprecedented," Garrett said. "We have a right to understand why it costs so much to terminate Alex Clifford's contract. That's the big question."

Garrett had long criticized Metra for what she contended was a lack of accountability. As a legislator, she pushed for a state law that put Metra under jurisdiction of the state's inspector general.

It's "inconceivable" for Metra's board to cut Clifford loose and not explain why, Garrett said. She proposed Monday that some sort of oversight committee "take a look at the inner workings" at Metra.

"There is no transparency," Garrett said. "Everything is happening behind closed doors."

The confidentiality clause includes "statements made by the parties in discussions of Clifford's employment," the document states.

Clifford's buyout was the subject of months of secret negotiations, after which officials declined to comment, citing a "personnel" exemption in public meetings law.

After Friday's 9-1 vote to approve Clifford's severance, board members, including Chairman Brad O'Halloran, again declined to discuss the agreement. The board is appointed by officials of the six counties and Chicago Mayor Rahm Emanuel.

O'Halloran referred inquiries to Metra's counsel, Andrew Greene, who deferred to the document itself.

Neither Greene nor O'Halloran responded to requests Monday to discuss the issue.

The confidentiality clause raises a number of questions, including why it was necessary for Metra and Clifford to negotiate the agreement in the first place and why it was necessary to impose a gag on both sides, especially since Metra is a public agency.

Steve Schlickman, head of the Urban Transportation Center at the University of Illinois of Chicago, wondered why Metra's directors simply didn't wait for Clifford's contract to expire and use the intervening time to find a new CEO.

"I've never heard of such a huge buyout of a contract ... of an agency of Metra's size ever, and certainly in Chicago," said Schlickman, the former executive director of the Regional Transportation Authority.

"I think it's really hard to explain (and) very hard for Metra to explain to riders and fare payers and also the taxpayers of Illinois," he said.

Clifford signed a three-year, $252,500-a-year contract with Metra that would have expired in February 2014.

Clifford couldn't be reached Monday.

With eight months left on his contract, Clifford is walking away with a severance package that could net him up to three times his annual salary