Chief Executive Leung Chun-ying said the project to build the northern part of the link between Tuen Mun and Chek Lap Kok was making good progress and was within budget. The chief executive yesterday visited the project site accompanied by Director of Highways Peter Lau Ka-keung - five days after a barge struck a bridge on the Lantau Link, forcing the closure of the main highway to the airport and inconveniencing thousands of air passengers. READ MORE: Calls for alternative to Lantau Link to Hong Kong airport after transport chaos Speaking at the entrance to the tunnels at the Tuen Mun site, Leung said the project was currently within budget. But he conceded: "Speaking of construction work in the sub-sea area, there may be unforeseeable factors [affecting construction] ... But the progress so far is good." Leung said the link could serve as an alternative route for people to get to Lantau and Hong Kong International Airport. The travel distance between Tuen Mun city centre and the airport will be shortened by 22km or about 20 minutes compared with travel via the Lantau Link. There have been suggestions that the chaos arising from the closure of the Lantau Link would have been eased if lawmakers had not voted down the Tuen Mun project back in 2002. Peter Lau said two largediameter boring machines were being used to create the tunnels at a rate of 15mm per minute. "We are digging the tunnel from the north to the south. The excavation has proceeded about 500 metres from this point," said Lau. "Sooner or later, we will reach the second vent shaft." The entire link comprises a 9km dual two-lane carriageway between Tuen Mun and North Lantau. The 5km sub-sea tunnels - the northern part of the link - connects Tuen Mun with the boundary crossing facilities for the bridge to Zhuhai and Macau and are scheduled for completion in late 2018. It will be further linked with the North Lantau Expressway via a 1.6km viaduct. Lau said the completion date for the viaduct was not set. The link from Tuen Mun to Chek Lap Kok is part of the Hong Kong-Zhuhai-Macau bridge project. Construction work on the Tuen Mun link began in mid-2013 after the Legislative Council's Finance Committee endorsed HK$44.8 billion in funding.