4 | HEX | Heathrow Express Operating Authority | Heathrow Express is a train service from Heathrow Airport to Paddington in central London operated by the Heathrow Express Operating Authority - a wholly-owned subsidiary of BAA. The service is not part of the National Rail system, despite part of its journey sharing track with National Rail trains and terminating at a London mainline station.http://www.heathrowexpress.com/ | GB | TRAFFIC |