The Tampa and Seattle-Tacoma Intra-terminal transit systems have been in service long enough to judge the validity of their concepts and the success of their designs. These two systems have been accepted by the Authorities that own and operate them. They have excellent safety and performance records. The public accepts their driverless cars routinely.The two systems are described and compared. They are similar in many respects but differ in their basic application to the airports, one being a shuttle and the other a loop system. As a result of their specific application, the automatic control systems differ.Operating and performance summaries are given. Both systems provide the same level of service and both have an availability over 99%.