Barbados is an up-and-coming tourist country that provides reliable and safe transport for natives and visitors alike. The country is very small with a length of 21 miles (34 km) long and 14 miles (23 km) wide. Barbados has 1,600 kilometres (990 mi) of public paved roads, two active marine ports in (Bridgetown Port and Port Saint Charles), remnants of a railway system, and one airport; the Sir Grantley Adams International Airport, located in Christ Church. As a former British colony, Barbados was heavily influenced by the English culture and customs which carried over into the infrastructure of Barbados. Similar to the driving habits in the United Kingdom, people in Barbados also drive on the left side of the road. Barbados has a very dependable highway system of main roads that stem from the country's capital, Bridgetown. The highways are identified by the numbers one to seven. H1 signifies the first highway that runs north. The numbering continues sequentially in a clockwise direction. The most popular highway throughout the island is the A. B. C. Highway (Adams/Barrow/Cummins). Throughout the Barbados roadways, the most prominent traffic junctions are the two lane roundabouts. Like roundabouts seen in the United States vehicles in the inner most lane of the roundabout have the right of way, however, in Barbados the traffic moves in clockwise direction. The speed limit on all roads is 60 km/h (37 mph) unless otherwise posted. The speed limit on the ABC Highway and the Spring Garden Highway is 80 km/h (50 mph).