The government will announce arrangements within a year for a trial scheme to allow private cars from Hong Kong and the mainland to drive into each other's jurisdictions on temporary one-off passes. Secretary for Transport and Housing Eva Cheng said the scheme might first be introduced at the under-used Western Corridor. The expressway links Ngau Hom Shek in the northwestern New Territories to Dongjiakou in Shekou. Answering legislators' questions, Ms Cheng said quotas for the temporary passes should take into consideration the capacity of the road networks on both sides, road safety, security and environmental concerns. Mainland cars could be tested for Hong Kong's emission standards before their owners could apply. 'Our target is to announce the arrangements for the first phase of the scheme within one year, while the actual implementation date will be worked out subject to the progress of discussions,' she said. Ms Cheng added that experts from both sides would need to discuss details such as the number of passes, the issuing criteria, application procedures, mutual recognition of vehicle licences, insurance and traffic enforcement. She said the plan was aimed at allowing private car owners who could not get regular passes to apply for the one-off passes. 'All information gathered about tested mainland cars will be used for setting up a data bank,' Ms Cheng said. 'We also want to make the application procedure convenient to users, such as by allowing them to apply via the internet.' She said views had already been exchanged with Guangdong authorities. Both sides agreed to implement the proposed scheme in two phases, starting with the issuing of passes for private cars from Hong Kong, followed by those from Guangdong. Ms Cheng said the proposed scheme would provide specified quota limits to allow mainland residents to drive their cars to Hong Kong. 'The number of ad hoc quotas may increase incrementally over the years in a gradual and controlled manner, or be adjusted flexibly having regard to seasonal demand.'