One of the best ways to navigate the twists and turns of the issue is to figure out whether the travel is mainly for your company's benefit or the employee's benefit. In general, you'll have to pay for travel that benefits you, but not for travel benefiting the worker.
Here are the most important rules to keep in mind:
Under the Fair Labor Standards Act ((register to read more)) and the Portal-to-Portal Act (an amendment to the FLSA), regular travel back and forth to work doesn't count as working time unless the employee actually does work en route. This is true even if your work site is a moving target. It doesn't matter whether the employee works at a fixed location or different job site...