Hong Kong Strategic Route and Exit Number System
The Hong Kong Strategic Route and Exit Number System (Traditional Chinese: 香港主要幹線及出口編號系統) is a system adopted by the Transport Department of the Hong Kong Government to organise the major roads in the territory into Routes 1 to 10 for the convenience of drivers. When the system was first implemented in 2004, the government launched a large campaign to promote it to the public. One of the slogans is "Remember the Numbers; Make Driving Easier" (認路記號碼，唔使路路查).
The system comprises nine major series of roads in Hong Kong, numbered Routes 1 to 5 and 7 to 10, which can be classified into three categories: the three north-south routes, the five east-west routes and the New Territories Circular Road. The route numbers are represented as black on yellow "road-shields" on overhead roadsigns.
The system also implemented exit numbering on the aforementioned routes. The exits of each route are numbered sequentially; some exit numbers are suffixed with a letter of the alphabet. Exit numbers are indicated by white in black rectangular boxes on overhead and roadside signs.
Route number system
The three north-south routes include Route 1, Route 2, and Route 3. They connect Hong Kong Island, metro Kowloon and the New Territories via a series of flyovers and tunnels. They pass through the three tunnels crossing Victoria Harbour, and their sequence of numbering follows the order of opening dates of the three tunnels:
- Route 1: Cross-Harbour Tunnel (opened 1972)
- Route 2: Eastern Harbour Tunnel (opened 1989; formerly Route 6)
- Route 3: Western Harbour Crossing (opened 1997)
The five east-west routes — Route 4, Route 5, Route 7, Route 8 and Route 10 — are numbered from south to north. The pattern indicates that Route 6 will most likely be built between Routes 5 and 7. Route 4 runs along the north shore of Hong Kong Island, connecting the eastern and western ends of the island, whereas Routes 5 and 7 link southern New Territories with different parts of Kowloon. Route 8 provides direct access to Chek Lap Kok Airport, and was extended to Sha Tin in 2008. Route 10 provides access to the border crossing at Shekou, Shenzhen.
- Route 4: formerly Routes 7 and 8 (opened 1990)
- Route 5: formerly Tsuen Wan - Ngau Tau Kok section of Route 2 (opened 1970-1980s)
- Route 7: formerly Route 4 (opened 1970s)
- Route 8: formerly Route 9 (Tsing Yi - Airport section opened 1997; Tsing Yi - Cheung Sha Wan section opened December 2009; Cheung Sha Wan - Sha Tin section opened 2008)
- Route 10 (opened 2007)
The circular route, Route 9, circumscribes the New Territories, with the exit at the Shing Mun Tunnels in Sha Tin as the starting point of exit-numbering. It links up the network of expressways and trunk roads in the New Territories into a large ring.
- Route 9: formerly Route 5 + Fo Tan - Lok Ma Chau section of Route 1 + Tsuen Wan - Lok Ma Chau section of Route 2 (construction from 1974–2007)
Exit number system
In parallel with route numbering, the junctions between routes and exits from routes are also labelled with exit numbers. On every route, exits are numbered from one end to the other with ascending consecutive integers with a mixture of alphabet-suffixed labels (1, 2, 2A, 2B, 3, 4... etc).
The first generation of the route number system in Hong Kong was envisaged in the 1968 Hong Kong Long Term Road Study by Freeman, Fox, Wilbur Smith & Associates, in which trunk routes were given single-digit numbers, and distributors with double-digit ones. Also included in the road study was an unnumbered Western Harbour Crossing (WHC), which in the plan involved a bridge crossing the Victoria Harbour between Cherry Street in Mong Kok and Kennedy Town, by way of Stonecutters Island and Green Island.
- 1: Aberdeen to Fanling, via Aberdeen Tunnel, Cross Harbour Tunnel, Lion Rock Tunnel, Tai Po Road
- 11: Ngau Tau Kok to Butterfly Valley Interchange, via Prince Edward Road East, Prince Edward Road West and Lai Chi Kok Road for westbound, Cheung Sha Wan Road and Boundary Street for eastbound
- 12: Kowloon City to Mong Kok, via Argyle Street and Cherry Street, connecting to WHC
- 14: connecting routes 1 and 4, via Choi Hung Road and Po Kong Village Road
- 2: Junction between route 1 and Chatham Road to Sheung Shui, via Gascoigne Road, West Kowloon Corridor, Kwai Chung Road, Tsuen Wan Road, Tuen Mun Road, Castle Peak Road
- 3: Junction between route 1 and Chatham Road to Yau Tong via Kai Tak Tunnel (then Airport Tunnel) and Kwun Tong Road
- 4: Butterfly Valley Interchange to Kwun Tong, via Ching Cheung Road, Lung Cheung Road and a suggested flyover of what was to become Kwun Tong Bypass
- 5: Kwai Chung to Sha Tin, via what was to become Shing Mun Tunnels
- 6: Castle Peak Road, Kwai Chung and Tsuen Wan sections
- 7: Aberdeen to Causeway Bay, via suggested road between Aberdeen and Kennedy Town, Connaught Road, Harcourt Road and Gloucester Road
- 8: Causeway Bay to Chai Wan via suggested flyover above King's Road; predecessor to present-day Island Eastern Corridor
The second generation of route numbers came into use in 1974. All distributors lost their numbers, retaining only trunk routes in the system. It was replaced in 2004 by the present-day third generation. At the new system's conception, some numbers were reserved for future road plans at that time. There were 11 routes in the system, of which nine (routes 1 to 9) were used as of 2004.
- 1: Aberdeen to Lok Ma Chau, 47.3 km, previously route 1. Split into routes 1 and 9
- 2: Ngau Tau Kok to San Tin, 54.4 km, previously routes 2 and 3. Split into routes 5 and 9
- 3: Sai Ying Pun to Au Tau, 27.7 km. Still route 3 today
- 4: Lai Chi Kok to Tseung Kwan O, via Kwun Tong Road, 17 km. Today's route 7
- 5: Tsuen Wan to Sha Tin Racecourse, 9.5 km. Part of route 9 today
- 6: Tai Koo Shing to Ma Liu Shui, via Kwun Tong Bypass and Tate's Cairn Tunnel, 19.5 km. Today's route 2
- 7: Causeway Bay to Aberdeen, 13.5 km, previously also route 7. Merged with route 8 to form today's route 4
- 8: Island Eastern Corridor, 9.6 km, previously also route 8. Merged with route 7 to form today's route 4
- 9: Chek Lap Kok to Tai Wai, 33.7 km. Today's route 8
- 10: Green Island to Shenzhen Bay, 29.5 km. Still route 10 today
- 11: West Kowloon to Tseung Kwan O, via Central Kowloon Route, 14 km. Today's route 6, still under planning
The third generation of route numbers came into use in 2004, and is the system used at present.