NEWARK, N.J. (CBSNewYork/AP) — New Jersey Gov. Chris Christie’s former deputy chief of staff testified Friday in her criminal trial that she told him about a traffic study on the George Washington Bridge before sending an email that it was “time for some traffic problems,” which prosecutors say started a political revenge plot.

Bridget Kelly is accused of plotting with two other former Christie allies to close lanes on the bridge that connects New Jersey and New York as revenge against a Democratic mayor who wouldn’t endorse the Republican governor’s re-election effort in 2013.

FULL CBS NEW YORK BRIDGEGATE COVERAGE

Breaking her silence for the first time in three years, Kelly testified in her own defense Friday. She maintained that she believed the lane closings to be part of a Port Authority of New York and New Jersey traffic study. She is on trial along with former Port Authority of New York and New Jersey executive Bill Baroni.

David Wildstein, a former Port Authority staffer, previously pleaded guilty in the case and is the prosecution’s key witness. The self-described mastermind of the plot, Wildstein has said the traffic study was just a cover story.

Kelly said Friday that Wildstein told her the traffic study would cause “tremendous traffic problems” in Fort Lee, but would ultimately help traffic flow. She said Wildstein suggested holding an event at the bridge with banners saying “Thanks, Governor Christie.”

As CBS2’s Meg Baker reported, Kelly said when she took the idea to Christie the governor responded by saying ‘That’s So Wally.’

Wally for ‘Wally Edge’ Wildstein’s political blog name.

Kelly said she warned the governor about potential traffic problems.

He then asked how their relationship was with Fort Lee Mayor Mark Sokolich, she said.

That’s when she sent the now infamous email — ‘time for some traffic problems in Fort Lee.’

The release of the “traffic study” email was what blew the scandal into full public view and led to Christie firing Kelly and his campaign manager, Bill Stepien.

“I’m pretty sure if I said it’s time for a traffic study in Fort Lee, we wouldn’t all know each other,” Kelly said.

On the stand Kelly said she as just using Wildstein’s words and wished she used the word ‘study.’

Sometimes in tears, Kelly depicted a constant state of anxiety working in Christie’s office. She also testified that Christie once threw a water bottle at her, angry that she suggested he introduce local political leaders at an unrelated event. She responded “yes” when her attorney asked her if she was afraid of Christie.

“As she testified it was an emotional experience,” attorney Michael Critchley said.

While on the stand, Kelly described being in a constant state of anxiety — in fear for her job is an event that she set up did not go as the governor planned.

One of those times was September 12, 2013, the last day of the lane closures.

There was a fire on the Seaside Park Boardwalk. Kelly was tasked with organizing an event between the governor and business owners effected by the fire for that Saturday.

While briefing the governor and suggesting that he start off by introducing everyone involved, she claims he said, “what do I look like, a (expletive) game show host?” Before throwing a water bottle at her.

Mike DuHaime, one of Christie’s top political advisers, testified that he told Christie ahead of a news conference two months after the lane closures that Kelly and Stepien knew about them.

WEB EXTRA: Timeline of key events in “Bridgegate” investigation

At the Dec. 13, 2013, news conference, Christie told reporters that no one in his administration other than Wildstein knew about the closings. Asked whether he could say with certainty that no other knew about the plot, Christie said that he had no reason to believe that.

He said he asked everyone on his senior staff to tell him if they had any knowledge “and they’ve all assured me that they don’t.” He said that Stepien “assured me the same thing.”

Stepien’s attorney has previously said his client did not engage in wrongdoing of any kind.

Christie has denied he had any knowledge about the lane closures and hasn’t been charged.

Critchley, has said he wouldn’t rule out calling the governor himself to testify.

“Considering calling anybody that I think is relevant by way of testimony that’s necessary to prove my client’s innocent, it includes everyone and excludes no one,” Critchley told WCBS 880’s Kelly Waldron. “We’ll just see. I’m not looking to make this sensational.”

A recent poll found 52 percent of New Jersey residents think there is sufficient proof that the governor knew about the closures and didn’t stop them.

Fort Lee residents also don’t buy the repeated denials.

“Something that big don’t go down unless somebody knows what’s going on and that’s coming right from the top,” one resident said.

“He’s the governor, how could you not know what’s going on?” another resident said.

(TM and © Copyright 2016 CBS Radio Inc. and its relevant subsidiaries. CBS RADIO and EYE Logo TM and Copyright 2016 CBS Broadcasting Inc. Used under license. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed. The Associated Press contributed to this report.)