Complex sentence: Terminal 5 at London Heathrow Airport is connected to its business passenger car park, just north of the airport, by a ULTra PRT system, which was built on behalf of BAA, the airport's owner and operator.
Split into simpler sentences: Terminal 5 at London Heathrow Airport is served by a ULTra PRT system that connects the terminal to its business passenger car park, just north of the airport. The line has been built on behalf of BAA, the airport's owner and operator.