I often get questions about whether an employee is entitled to be paid for time he or she spends driving to a job site or driving between differnt job sites during the day. In Texas, this area of the law is largely controlled by federal law, namely the Fair Labor Standards Act ("FLSA").
Under the FLSA, time spent traveling during normal work hours is considered compensable work time. Time spent in home-to-work travel by an employee in an employer-provided vehicle, or in activities performed by an employee that are incidental to the use of the vehicle for commuting, generally does not have to be paid. This commuting exception applies only if the travel is within the normal commuting area for the employer's business and the use of the vehicle is subject to an agreement between the employer and the employee.
So, a good general rule of thumb is to think of it in terms of commuting. The FLSA does not require an employer to pay you for what would be considered a normal pre-work or after-work commute - even if it is to a different location in town than your normal workplace. However, requiring you to drive to another city or another work site during normal working hours is generally considered to be compensable and must be paid.