"The end is in sight," he said. "We have to tie up some loose ends and develop a consensus on what our recommendations and findings are."
Christie, a possible contender for the presidency in 2016, is raising money across the country for this year's GOP candidates and assuring donors and the conservative electorate that the bridge scandal is behind him.
Yet federal prosecutors are conducting a criminal probe into the lane closures, though they do not publicly disclose details. Law enforcement agencies are also said to be investigating separate operations at the Port Authority of New York and New Jersey, which runs the bridge, and the business interests of its former chairman.
Lanes were closed for four days in September, allegedly at the direction of Christie allies bent on political retribution against the Democratic mayor of Fort Lee, Bergen County, who didn't endorse the Republican governor for reelection.
One of the central questions remains unanswered: Who ordered the lanes closed and why? The legislative committee may never know: Several key figures, backed by a state judge, have declined to comply with subpoenas, citing their Fifth Amendment rights against self-incrimination.
Wisniewski said the investigation has revealed that the Port Authority operates more like a department within the governor's office than as an independent agency.
That dynamic, he suggested, allowed Bridget Anne Kelly, Christie's former deputy chief of staff, to successfully orchestrate the lane closures.
Kelly, whom Christie fired in January, wrote in an Aug. 13 e-mail: "Time for some traffic problems in Fort Lee." Former Port Authority official David Wildstein responded: "Got it." He resigned in December.
Kelly's attorney, Michael Critchley, said in an e-mail Thursday: "Any suggestion that my client had the authority or motive to close lanes leading to the entry of the George Washington Bridge is nothing more than speculation and guesswork."
The administration's "operational" involvement, Wisniewski said, "calls for systemic reform both at the Port Authority and within the governor's office."
The committee's investigation also has revealed "a remarkable absence of any self-examination or curiosity" within the Christie administration, Wisniewski said.
Current and former administration officials have indicated to the committee that they asked few questions about the lane closures as they learned about them. Some said they thought the bridge issue was being drummed up for political purposes before the November election.
Christie's press secretary, Michael Drewniak, for example, told legislators in May that he didn't suspect anything improper, in part because he considered the legislators drawing attention to the lane closures - Wisniewski, a former chair of the state Democratic Party, and Senate Majority Leader Loretta Weinberg (D., Bergen) - as "two of the most partisan members of the Legislature on the other side of the aisle."
The committee also has heard from Christie's chief of staff, Kevin O'Dowd; a former aide to Kelly, Christina Renna; a former staffer for the governor's reelection campaign, Matt Mowers; and Port Authority Commissioner William "Pat" Schuber.
Christie's incoming chief of staff, Regina Egea, is scheduled to testify July 17.
Not every member of the legislative committee thinks the investigation has served the public good.
"What I've learned is that there is a limitless potential for this committee to waste money and time given that it has no clear goal and no cap on its expenses," said Assemblywoman Amy Handlin (R., Monmouth).
Lawyers retained by the committee billed it for more than $700,000 through March, invoices show. Separately, the Gibson Dunn & Crutcher L.L.P. firm billed the governor's office for more than $3 million through February. It released a report in March clearing Christie of any wrongdoing. All of the expenses are to be paid by taxpayers.
Handlin said the Port Authority's dysfunction was evident and thinks the committee should shift its focus toward improving its operation and let law enforcement handle the deeper investigation into what happened at the George Washington Bridge. On Thursday, a special panel wrote in a letter to Christie and New York Gov. Andrew Cuomo that it was reviewing the agency's core mission, governance, and operation.
Handlin said the committee had learned "many trivial things about problems" in various administration departments. But the "only really valuable insight is one that we certainly didn't need dozens of hours of hearings and a highly paid lawyer from Illinois in order to discover, and that was simply that David Wildstein and Bridget Kelly, and perhaps one or two others at the Port Authority, appeared to have cooked this up and executed the plot themselves."
Wildstein's attorney did not respond to a request for comment.
For his part, Christie, who in January said on national television that he was "embarrassed and humiliated" by his staff, has attempted to move past the scandal that threatened to upend his political ascent.
Of the legislative hearings, he said in May: "Absolutely nothing new has come out of this."