New Jersey Governor Chris Christie, who is accused of deliberately creating congestion in an apparent act of political retribution, says he may have known about the traffic but not that his aides had ordered lanes blocked.
During an hour-long radio call-in, the possible 2016 presidential candidate fielded questions for the first time in three weeks about a scandal that has engulfed his administration and threatened to end any political ambitions.
Christie has already apologised but denied any involvement in his top aides apparently closing two lanes on the George Washington Bridge, which links his state to New York City, to punish a local mayor with massive traffic backups.
The Republican governor also acknowledged in the call-in that his office has been subpoenaed by federal law enforcement officials conducting a criminal investigation into the bridge scandal.
Christie said his office would fully comply with the document request.
Christie, 51, reiterated during the radio show that he did not know about the planning or execution of the lane closures near the bridge in Fort Lee.
He disputed the account of a former loyalist, who said on Friday there was evidence the governor knew about the closures while they were happening over four days in September, which is earlier than Christie has acknowledged.
Christie said an email from Patrick Foye, the executive director of the Port Authority of New York and New Jersey, the agency that runs the bridge, made him realise the traffic gridlock may not have been routine.
That email was forwarded to a top Christie aide on September 13, the day Foye ordered the lanes reopened.
"I know prior to (the Foye email) there were press accounts about traffic issues up there, and if I read that or someone said something ... it wouldn't have been meaningful to me because I didn't know there was any problem up there because I didn't know we had actually closed lanes up there before that," Christie said on TownSquare Media's "Ask the Governor" show.
"Nobody has said I knew about this before it happened, and I think that's the most important question," he said.
Christie has been asked before when he learned of the lane closures, which has cost five people close to the governor their jobs.
During a December 13 news conference, he said, "It was certainly well after the whole thing was over before I heard about it."
Monday was the first time Christie took questions since David Wildstein, Christie's No. 2 man at the Port Authority before he resigned amid the scandal, contradicted the governor's accounting of the lane closures.
Christie referred to the dispute over what he knew when as "a game of gotcha."
Meanwhile, a former Christie aide who set the lane closures in motion with an email to Wildstein has invoked her right not to incriminate herself and is refusing to co-operate with a subpoena from a legislative committee looking into the scandal and trying to unravel how high up Christie's chain of command the lane closing order went and whether the operation was meant to punish a Democratic adversary.