Fresh concern about whether the new airport will open on time was sparked yesterday when the North Lantau Expressway was found to be sinking. Urgent repairs were under way on three sections of the road which were built on reclaimed land. The Highways Department said that the reclaimed land was 'settling' in the Tai Ho Wan, Siu Ho Wan and Sham Shui Kok sections. It said the highway, which opened to traffic only a year ago, had sunk as much as 25 cm in about 100 to 200 metres of road in each of the three sections. Democratic Party spokesman on infrastructure Albert Chan Wai-yip voiced his concern that the sinking could affect access to the new airport at Chek Lap Kok. 'I am astonished by this news which is of definite concern as the airport is due to open soon,' Mr Chan said. 'There are many major roads built on reclaimed land in Hong Kong, such as Tolo Highway and the Island Eastern Corridor. I am amazed that with all this experience we are having problems with the North Lantau Expressway.' But a Highways Department spokesman said its engineers found no cracks and described the settlement as minor. 'This always happens with reclaimed land - drivers don't even notice,' she said. The spokesman added that repair works to re-elevate the highway should be completed before the airport opens. A highway maintenance vehicle ran into the back of a bus on Monday afternoon in one of the sections being repaired. The driver, who had lost control of the vehicle, was trapped for 30 minutes before being freed by firemen.