A 20-year-old woman has been missing from Montgomery County, Pennsylvania for three days, after her car allegedly broke down on the side of the road.

Deirdre Magolon was last seen leaving her Royersford home around 6:40 and 7pm on Friday.

At 11:30pm that same night, authorities found Magolon's 2005 black Mazda 'abandoned and unoccupied on eastbound Route 422 near King of Prussia - about a 20 minute drive from her home.

Without a trace: Deirdre Magolon has been missing from Montgomery County, Pennsylvania for the last three days

Family members believe her car broke down, and says she didn't have a phone on her at the time.

Magolon hasn't been seen since, Upper Providence Township police say.

She has been described as 5-foot-5, with blonde hair and blue eyes and was last seen wearing a gray furry hooded jacket.