I’m including an excerpt from a global guidance document (which we are issuing in 2012) addressing fatigue that relates to the question posed. We don’t have a global policy on this matter; however, standards at the op co may be developed and enforced at the local level.

JET LAGJet lag is a condition that travelers may experience when flying across time zones. Extremely long flights (i.e., international travel) or flights with multiple segments can leave the traveler exhausted upon arrival, and may be a factor in road fatalities. Instead of renting and driving a vehicle, strongly consider taking a shuttle or other form of transportation to your hotel or other destination, or if you are coming home late, arrange for someone to pick you up at the airport or if necessary, stay the night in a hotel. Don’t take unnecessary risks.