Metro Manila is the capital region of the Philippines, composed of 16 cities and one municipality covering an area of 636 square kilometers. It has a population of over 11 million people and is the center of political, economic, social and cultural activity in the country. The region has experienced rapid urbanization and population growth since the mid-20th century, resulting in high population density and traffic congestion challenges. Traffic congestion costs the Philippine economy over $3 billion annually and results from an imbalance between private vehicle usage and limited road infrastructure in Metro Manila.