The government should seriously consider moving the border checkpoint of the proposed Hong Kong-Macau-Zhuhai bridge from east of Chek Lap Kok airport to the western side to minimise its environmental impact, activists said. An alliance of activists, including environmentalists and community groups, said yesterday that moving the bridge's border checkpoint would not only preserve a coastal protection area on the airport island, but could cut visual and noise disturbance for about 30,000 Tung Chung residents. Their proposal would stop the link road, which is to connect the bridge to the border checkpoint, from passing through the sensitive reddish shoreline between the airport island and Lantau North. However, that would mean the government would have to build a separate route north of the airport to link the road to a New Territories-bound bypass, which officials said would raise the cost by as much as HK$13 billion. Alliance spokesman Paul Zimmerman said he believed that figure was an overestimation, as it included a tunnel option the alliance said was not needed. The Highways Department said earlier that building a road on the north coast of the airport was not optimal, as the area was reserved for the airport's third runway, and a road parallel to the runway might confuse pilots during landing. But Mr Zimmerman said many big roads were built around airports overseas. The department said the government's suggested location for the border checkpoint was best, as it was farther away from the habitat of the white dolphins and close to the proposed Tuen Mun-Chek Lap Kok Bypass, MTR stations, AsiaWorld-Expo and ferry services to the mainland. Jeff Lam, representative of two big private estates in Tung Chung, said it was also very near - just one kilometre - to the Tung Chung town centre. 'Why should Tung Chung residents pay the economic and social costs?' he asked. The alliance urged any opponents of the plan to submit objections before a public consultation ended on August 12.