But there may be a build-up of congestion over the next few days Traffic slowly picked up at the Cross-Harbour Tunnel yesterday, with 2,700 more vehicles using the route than on Tuesday, signalling a possible build-up of congestion in the next few days. Yesterday was the second working day after the Eastern Harbour Tunnel toll rise on Sunday. The increase included about 400 goods vans, which are expected to gradually return to the roads after this week's 'golden week' holiday. This followed a drop of 2,100 vans using the three tunnels on Tuesday. Yesterday's morning rush hour started half an hour early at 7.15am, but the congestion was comparable to any other weekday, transport officials said. So far, congestion at the cheaper Cross-Harbour Tunnel has not been as bad as expected, but government officials are not letting their guard down. Secretary for Environment, Transport and Works Sarah Liao Sau-tung reiterated that motorists needed to stay vigilant and listen to traffic news before leaving home. With tourists leaving town at the end of the 'golden week' holiday, she said she expected congestion tomorrow. 'Colleagues at the Transport Department have been working very hard to manage traffic and make it smoother,' Dr Liao said. 'The public should understand that everyone has to work together to solve traffic congestion. 'The government will continue to negotiate with the two [other] tunnel companies on a solution for the long-term traffic congestion.' Ricky Wong Kay, chairman of Hong Kong Container Tractor Owners Association, said trucks would return to the roads next week as mainland factories opened after the holiday, and he warned that most would take the Cross-Harbour Tunnel to save money. Despite the modest increase in vehicles travelling on the roads yesterday compared with Tuesday, the overall number was still lower than an average work day. Transport officials said that as of 3pm yesterday, there was an overall decrease in traffic of 6 per cent, or about 7,800 vehicles. The Cross-Harbour Tunnel saw a 1 per cent drop, or 700 vehicles, while the Western Harbour Tunnel recorded an 8 per cent increase of 1,800 vehicles. About 8,900 cars shunned the Eastern Harbour Tunnel, leaving the crossing with a 22 per cent decrease in customers. With fewer people taking their cars to work, the MTR Corporation once again reported a rise in the number of passengers during yesterday's morning rush. A company spokeswoman said 11,600 more passengers took the train between 7am and 9am - a 2.6 per cent increase. An extra train on each of the Tseung Kwan O and Kwun Tong lines handled the increase. The overall rise in MTR passenger traffic on Tuesday was 7.5 per cent, or 170,000 people.