Tuen Mun Road is a major expressway in Hong Kong which connects Tuen Mun with Tsuen Wan, within New Territories. It is part of Hong Kong's Route 9, which circumnavigates the New Territories. Built in 1977, it was once the major trunk route linking the northwest New Territories to urban Kowloon and is known for its frequent traffic jams and road accidents owing to its early design and heavy usage. As a result, speed limits have been enforced to 70–80 km/h (45–50 mph) due to geometric constraints.