Transport experts say a trial scheme allowing disabled people to alight from private cars in restricted zones should be expanded to include school children. The six-month Transport Department trial began this month allowing disabled people to issue certificates to drivers dropping off or picking them up in a restricted area. The certificate exempts drivers from prosecution. Welcoming the move, Hong Kong Automobile Association chief executive Kendy Chan Kin-chung said it should also include school buses, many of which are forced to drop off children several blocks away from school. Senior transport officer Irene Ho Wai-yin said permits may be offered to bus firms or schools to drop off in restricted zones, but only under special circumstances. 'A permit may be offered, but it is quite strict as these restricted zones are quite busy and stopping can cause danger to other traffic,' Ms Ho said. 'Whether they can receive a permit depends on the location and the times they wish to use the zones.'