Great question.
Travel from Job Site to Job SIte:
The IWC Orders specifically define the term "hours worked" as time during which the employee is subject to the control of an employer, and includes all the time the employee is suffered or permitted to work, whether or not required to do so. C.C.R. 11010(2)(G). Under California law, if the travel is at the direction of the employer, the employee is subject to the control of the employer during the travel time. This means that your commute time from work site to work site must be compensated at your regular rate of pay or at the overtime rate, if applicable. As Mr. Chandler pointed out above, your initial commute from home to the first site and from the last site back home at the end of the day is likely to not be compensable as this would be similar to the commute of any other person who commutes to and back from just one work site every day.
Expenses
Under Cal. Labor Code section 2804, you are entitled to reimbursement of any and all reasonable and necessary expenses incurred in discharging your duties to the employer. Thus, you are entitled to reimbursement.
Of course, if you are an independent contractor, the answer to both of the above questions would likely be "no."
Thanks, and feel free to follow up.
Arkady Itkin
San Francisco & Sacramento Employment Lawyer