Transportation and communicationsThe Henry E. Rohlsen International Airport serves St. Croix and the Cyril E. King International Airport serves St. Thomas and St. John. The U.S. Virgin Islands are the only United States territory which drives on the left. This was inherited from what was then-current Danish practice at the time of annexation, to limit losses of livestock. However, as most cars being imported from the mainland United States are left-hand drive, the driver sits to the outside of the road, raising traffic safety issues.
U.S. Virgin Islands mail service is handled by the United States Postal Service, using the two-character state code "VI" for domestic mail delivery. Zip codes are in the 008xx range. As of January 2010, specifically assigned codes include 00801-00805 (St Thomas), 00820-00824 (Christiansted), 00830-00831 (St John), 00840-00841 (Frederiksted), and 00850-00851 (Kingshill).The islands are part of the North American Numbering Plan, using area code 340, and island residents and visitors are able to call toll-free U.S. numbers.
