BRENTWOOD -- A San Jose woman possibly trying to U-turn from a parallel parking spot into lanes going the opposite direction was killed Friday night when an oncoming vehicle broadsided her car, according to the California Highway Patrol.

The collision was reported about 9:20 p.m. on Vasco Road, about a half-mile from its intersection with Camino Diablo Road, CHP spokeswoman Sgt. Diana McDermott said.

A 30-year-old San Jose woman driving a Geo Tracker appeared to have attempted a U-turn from the northbound shoulder, across a double-yellow traffic line and into the southbound lanes, McDermott said.

That put her in the path of a northbound Toyota Camry traveling between 50 mph and 55 mph, which broadsided the Geo, killing the woman, McDermott said.

It was not clear whether the man driving the Camry required medical attention, she added.

CHP is still investigating the collision, and a key factor will be finding out whether the Geo's lights were on at the time of the crash, McDermott said.

The woman's name was withheld Saturday morning as officials tried to contact her family.

Contact Sean Maher at 925-943-8013. Follow him on Twitter at twitter.com/OneSeanMaher.