TRANSPORT chief Robert Footman said yesterday it would be too expensive to install seat belts in minibuses, following a crash that left one person dead and 13 injured. He was speaking as four people injured in the smash between a minibus and a car in Sha Tin on Friday remained in critical condition in hospital. 'Seat belts in minibuses need something very firm to secure them to,' the Commissioner for Transport said. 'As I understand, minibuses are not constructed in that way. It would involve quite a significant change in the construction, and that can be very, very costly.' He said there were complaints from time to time about speeding minibuses, particularly at night. 'We take these up with the trade and we will also refer such complaints to the police,' he said. The department is also exploring the possibility of installing a speed warning system on minibuses. In Friday's crash, four passengers were thrown from a Mongkok-bound minibus when it lost control, toppled on to its side and rammed into railings at the junction of Tai Chung Kiu Road and Sha Tin Rural Committee Road. Police said both the minibus and the car may have been travelling above the 50km/h limit. Two other passengers were in serious condition last night, while six were described as stable. One other person involved was discharged on Friday. Cheung Chi-hung, 22, the car's front-seat passenger, was certified dead on arrival at Prince of Wales Hospital.