About 60 motorists staged a slow-drive protest yesterday against the $100 departure tax on vehicles crossing into the mainland. The protesters set off from Kwu Tung in Yuen Long and drove via Fairview Park to Lok Ma Chau, where they disbanded peacefully. The Sino-Hong Kong Private Cars Rights Association, which organised the protest, said the boundary-crossing improvement tax, introduced by the financial secretary, was unfair. The protesters said they had to pay $100 per car regardless of the number of passengers on board, while travellers taking public transport were only required to pay $18 per person. The money is intended to improve checkpoint facilities. The association said most cars crossing the border were doing so for commercial purposes, and the charge might also confuse overseas investors. 'It will ultimately hurt economic activities between Hong Kong and the mainland,' said Cheung Ying-kit, a spokesman for the group. 'Some manufacturers might simply relocate their backup services across the border. 'It is unwise to impose the duty on the basis of vehicle trips rather than the number of passengers. It will become a heavy burden for the car operator as, most of the time, the cars crossing the border carry no passengers.' He said the tax should be charged according to the number of passengers. A letter expressing their views has been sent to Financial Secretary Antony Leung Kam-chung. Under the proposal, travellers who frequently cross the border, like drivers and students, would be exempt from paying the duty. At present, about 9,000 private cars in Hong Kong are licensed to cross the border. They are mainly owned by businessmen who have investments on the mainland and car-hire companies. Last year, these vehicles made more than two million trips across the border.