A woman driver who veered off Interstate 805 in Serra Mesa and struck a guardrail, part of which smashed through the passenger compartment, was seriously injured today.

The southbound vehicle crashed near Mesa College Drive shortly after 1 p.m., according to the California Highway Patrol.

Emergency crews freed the woman from the heavily damaged sedan, and medics stook her to Sharp Memorial Hospital for treatement of "major" injuries, the CHP reported.

Apparently no other vehicles were involved.