(BCF) for both mainland China and Macau in the west, to the Hong Kong Link Road in the east. This section includes and a 6.7-km () immersed tube undersea tunnel that runs between two artificial islands, the Blue Dolphin Island on the west and the White Dolphin Island on the east. The viaduct crosses the Pearl River estuary with three cable-stayed bridges spanning between 280 and 460 metres (920 and 1,510 ft), allowing shipping traffic to pass underneath. Hong Kong Link Road Under Hong Kong jurisdiction, the Hong Kong Link Road was built to connect the main bridge-tunnel to an artificial island housing the Hong Kong Boundary Crossing Facilities (HKBCF). This section includes a 9.4-km () viaduct, a 1-km () Scenic Hill Tunnel and a 1.6-km (1.0-mi) at-grade road along the east coast of the Chek Lap Kok. Zhuhai Link Road The Zhuhai Link Road starts from an artificial island housing the Boundary Crossing Facilities for both mainland China and Macau, passes through the developed area of Gongbei via a tunnel towards Zhuhai, and connects to three major expressways, namely, the Jing-Zhu Expressway, Guang-Zhu West Expressway and Jiang-Zhu Expressway. Left- and right-hand traffic Although the HZMB connects two left-hand traffic (LHT) areas, namely Hong Kong and Macau, the crossing itself is right-hand traffic (RHT), the same as in Zhuhai and other regions of Mainland China (the bridge is technically in Zhuhai for most of its length). Thus, drivers from Hong Kong and Macau need to make use of crossing viaducts to switch to RHT upon entering the bridge, and back to LHT upon leaving the bridge when they are back to Hong Kong and Macau. Traffic between Zhuhai and the bridge requires no left-right conversion as they are both RHT. Transport Shuttle buses The HZMBus shuttle bus service (colloquially referred as the "golden buses") runs 24 hours a day with bus departures as frequent as every five minutes. The journey across the HZMB takes about 40 minutes. The HZMB Hong Kong Port can be reached from Hong Kong by taxi or various buses including Cityflyer airport routes A11, A21, A22 and A29, Long Win Bus airport routes A31, A33X, A36 and A41, the B4 shuttle bus from Hong Kong International Airport, the B5 shuttle bus from Sunny Bay MTR station, or the B6 bus from Tung Chung. In addition, all overnight airport buses (NA-prefixed routes) terminate and start service from