If a truck driver from out of state is operating in California, they are still subject to California's trucking regulations and can be held liable for violations of those regulations. The California Highway Patrol (CHP) has the authority to enforce regulations on all commercial vehicles operating within California, regardless of where the driver is from.

If an out-of-state driver is found to be in violation of regulations while operating in California, they may be subject to fines or other penalties, just like a California-based driver. The trucking company that employs the out-of-state driver may also be held liable for any violations committed by the driver while operating in California.

In the event of an accident involving an out-of-state truck driver, the driver and trucking company may still be held liable for any damages or injuries caused by the accident, depending on the circumstances. It is important for all commercial drivers operating in California to comply with the state's regulations to avoid liability and ensure the safety of all road users.