Quick answer: Drive it only if lights, wheels, steering, and fluids are all intact, nothing is dragging, and no warning lights are on. A cracked bumper cover alone is usually drivable; anything touching wheels, lamps, leaking fluids, or deployed airbags means stop and tow.
Do not drive if any of these is true
A wheel is visibly tilted or the steering pulls hard (suspension damage); any fluid is trailing on the pavement (coolant, oil, transmission fluid); a headlight or brake light is out; the hood latch is damaged (a hood that flies open at speed is catastrophic); airbags deployed; a door won't stay shut; you smell fuel; or any part — bumper cover, splash shield, trim — is dragging or could tear loose onto the road. In California, driving with dragging parts, missing lights, or an unsecured hood can also earn you an equipment violation on top of the danger.
The "just cosmetic" trap
If it's a scuffed or cracked bumper cover with everything else intact, short-term driving is usually fine mechanically. Three cautions, though. First, modern bumpers are not chrome battering rams — the plastic cover hides an energy absorber and reinforcement bar, plus parking sensors and radar on many cars. A cover that looks “cosmetic” is often the wrapper around crushed absorbers, and a damaged bumper assembly may not protect you properly in a second impact. Second, if sensors were hit, driver-assist features may misbehave without a warning light. Third, loose covers get worse at freeway speed; a $400 re-secure becomes an $1,800 replacement when the cover tears off on I-880.
The smart move either way
Get the vehicle looked at promptly even if it drives fine. A quick inspection catches hidden damage while the insurance claim is fresh — hidden damage discovered months later is much harder to attribute to the accident. Take photos at the scene, and if the car isn't safe, your insurer's roadside coverage or the at-fault carrier typically pays the tow to the shop of your choice (that choice is yours in California, not the insurer's).
Spark Collision Center in Fremont does free drivability checks — swing by 40923 Albrae St, Mon–Fri 8–5 or Sat 8–12, and we'll put eyes on it, zip-tie what needs securing, and tell you straight whether it's safe to keep driving while parts are ordered.