California Mileage Reimbursement Law requires employers to reimburse employees for all vehicle expenses incurred on the job. Mileage reimbursement refers to the payment employees receive for using their personal vehicles for work purposes.It is lawful for your employer to make you use your own vehicle to drive to various locations for your job. This law states that employers should reimburse employees for each and every expense that they incur throughout the course of doing business. Under California law, commuting time to and from work normally does not constitute "hours worked" and is not compensable. This law states that employers should reimburse employees for each and every expense that they incur throughout the course of doing business. There's no legal responsibility one way or the other. Use or Possession of Alcohol or Cannabis Products in a Vehicle. The law is very strict about carrying alcohol or cannabis products in your vehicle with you.