FREMONT -- A Fremont police employee who suffered major injuries in a motorcycle crash with a truck and patrol car Friday was upgraded to stable condition Monday after spending much of the weekend in the intensive care unit, officials said.

The civilian employee, who authorities did not identify, was off-duty from her job in the Fremont Police Department's Records Unit when she was driving her motorcycle on Fremont Boulevard about 3:55 p.m., police spokeswoman Geneva Bosques said. The 29-year-old woman, an employee with the department for the past 18 months, was headed north when her motorcycle, a Fremont patrol car and a civilian truck collided with each other just past Thornton Avenue.

While authorities on scene could see that the patrol car collided with the motorcycle and the motorcycle collided with the truck, investigators are still working to determine the chronological sequence of those events, Bosques said. The woman was taken to the hospital with major injuries after being thrown about five feet from her motorcycle, while the driver of the truck and police officer in the patrol car were uninjured.

According to Bosques, the woman was wearing full protective gear including a helmet, rash guards and riding boots, which Bosques said "definitely prevented her from being more seriously injured" in the crash. The woman received no head trauma, though she spent much of the weekend in the ICU being treated for other undisclosed injuries.

"I can tell you she's in good spirits, and there's a lot of optimism about her recovery," said Bosques, who added that several Fremont police officers visited the woman in the hospital over the weekend.

Because the crash involved two Fremont police employees, outside investigators from the Tri-City Accidents Investigations Team, a collaboration between Fremont, Union City and Newark, will probe the cause of the crash.

"(Fremont police) are not investigating the cause or factors in the collision," Bosques said. "Newark has taken the lead on the investigation, and Union City will support them."

Newark police could not be reached for comment Tuesday afternoon, though Bosques said their investigation is ongoing.

Contact Erin Ivie at eivie@bayareanewsgroup.com. Follow her at Twitter.com/erin_ivie.