Hopewell Holdings might have underestimated the traffic impact of its new Hopewell Centre II hotel, according to a traffic expert who has challenged the Transport Department's decision to approve the impact assessment. Hopewell Holdings announced its traffic impact assessment had been approved by the Transport Department, clearing the last departmental hurdle to the building of the 55-storey convention hotel in Wan Chai. But Hung Wing-tat of Polytechnic University said the assessment report was full of questions. The report assessed the impact on four junctions and said traffic along Queen's Road East had been declining by around 1 per cent a year. 'It is impossible for Wan Chai to experience a negative growth rate of traffic when the Transport Department predicted a 4 to 8 per cent growth in the whole territory,' Professor Hung said. Instead of adopting the department's model to project growth rates, the report used a statistical technique known as regression analysis, which Professor Hung said was conducted in an unscientific way. Professor Hung also said the assessment had missed a junction at Cotton Tree Drive and Kennedy Road and he questioned the hotels used for comparison. 'The new hotel is supposed to be a top one, so why wasn't it compared with the major five-star hotels in the neighbourhood?' he said. 'The department should not have accepted a report of such quality.' A Hopewell Holdings spokesman said the traffic consultant company hired was well established and the report was based on the standard requirements for a traffic impact assessment.