Thousands of motorists abandoned their cars for public transport yesterday to avoid potential traffic jams at the Cross-Harbour Tunnel on the first working day after the Eastern Harbour Tunnel toll increase. But the full impact of the change has yet to be seen as hundreds of trucks have not yet returned to the roads following the Labour Day holidays. About 4,000 extra passengers travelled on MTR trains across the harbour between 8am and 9am. The rail operator had to deploy extra trains on the Kwun Tong, Tseung Kwan O and Hong Kong Island lines. As of 3pm, the company reported 14,000 additional passengers, a 1 per cent rise on normal numbers. Bus companies said the number of passengers using tunnel buses remained about the same, but the Star Ferry Company reported an increase of 25,000 passengers, or 29 per cent, between 7am and 11am. Traffic at the Cross-Harbour Tunnel was smoother than usual during the morning rush hour. Many drivers left 15 to 30 minutes earlier to avoid anticipated traffic congestion. But between 6am and 10am, the tunnel carried 300 fewer vehicles than normal, according to the Transport Department. The number of vehicles using the three harbour tunnels was 4,160 down on normal numbers. Both HKCEE and A Level exams started on time despite earlier concerns students would be late because of traffic jams. Transport minister Sarah Liao Sau-tung thanked the media and public for helping prevent traffic chaos. 'We are very grateful that citizens played their role and have taken heed of government suggestions and stretched out their travelling during the peak hours,' she said. 'We hope that after this experience people in Hong Kong will think about how they travel to work every day.' Dr Liao said one of the reasons there were fewer vehicles on the roads was because of the holiday on the mainland, which meant some travellers and commercial vehicles might not have returned.