There are 113 kilometres (70 mi) of roads. The main airport, Terrance B. Lettsome International Airport, also known as Beef Island Airport, is located on Beef Island, which lies off the eastern tip of Tortola and is accessible by the Queen Elizabeth II Bridge. Cape Air, LIAT and Air Sunshine are amongst the airlines offering scheduled service. Virgin Gorda and Anegada have their own smaller airports. Private air charter services operated by Island Birds Air Charter fly directly to all three islands from any major airport in the Caribbean. Helicopters are used to get to islands with no runway facilities; Antilles Helicopter Services is the only helicopter service based in the country. The main harbour is in Road Town. There are also ferries that operate within the British Virgin Islands and to the neighbouring United States Virgin Islands. As in the UK and in the United States Virgin Islands, cars in the British Virgin Islands drive on the left, however they differ in that nearly all cars are left hand drive, being imported from the United States. The roads are often quite steep, narrow and winding, and ruts can be a problem when it rains. Cyril E. King Airport in the US Virgin Islands has flights to a wider range of destinations, so is also used for travelling to the British Virgin Islands.