Employees' typical home-to-work commutes are not compensable time, and that doesn't change just because employees meet up at a designated place and take a car pool or van pool to work.
Those car-pool hours are unpaid even if the employees occasionally discuss work during the commute and even if the employer encourages (but doesn't require) car pooling.
Recent case: William Smith and other gas rig employees sued Aztec Well Servicing when Aztec refused to pay for the time they spent commuting to the well on which they'd work.
The rig workers always car-pooled with their crew leader because the wells were in remote areas—reached only by traveling in a pickup truck—and because of limited parking at the wells. They met at a designated place, parked their personal cars and headed out.
While driving together, they often discussed work issues. If the truck suffered a flat or had mechanical trouble, they all pitched in.
Still, none of this persuaded the 10th Circuit that the commuting time should be compensated under the. The court said all workers were free to drive on their own or to spend their car-pool time as they chose, including reading or sleeping. Therefore, they were not performing work on behalf of their employer, even if their commuting arrangement benefited the company. (Smith, et al., v. Aztec Well Services Company, No. 04-2153, 10th Cir., 2006)
Bottom line: Unless you require employees to travel together, it's unlikely that the travel time will be considered "work time." However, if you insist that employees car-pool or require them to make certain work-related stops along the way, you should pay for the time. The more benefit your organization derives from the arrangement, the more likely a court will say the commute is compensable.