The number of Hong Kong people living, or owning a home, across the border would almost double over the next 30 years as integration with the mainland sped up, government planners have forecast. Officials estimate that by 2030 more than 315,400 people from the SAR will own a home, work or study across the border - up from the present 179,200. Behind the rise is the rapid expansion and liberalisation of Hong Kong's transport infrastructure, most notably the KCRC's proposed Lok Ma Chau spur line and almost certain 24-hour border opening. A government study, Hong Kong 2030: Planning Vision and Strategy, also cites lower prices across the border and the development of transport networks on the mainland. Chief town planner Alfred Lau Yiu-kwong said as integration deepened between Hong Kong and the wider Pearl River Delta, he envisaged a relationship similar to that between New York and New Jersey, where people moved freely back and forth according to market forces. He said most of the 315,400 would still treat Hong Kong as their first home and spend much of their time here. 'Some of them will return more frequently than others, but all these people will basically still live in Hong Kong, demanding land resources.' Mr Lau said that better transport infrastructure such as the proposed Lok Ma Chau spur line and the extension of Lowu border facilities would make it easy to cross the border. He said Shenzhen and Guangdong had long-term plans to merge their rail systems, which would shorten travel times. 'With better infrastructure both within the delta and between Hong Kong and the mainland, a trend towards a mobile population will inevitably develop,' Mr Lau said. 'Hong Kong, with its leading role as a world-class city, could retain quality professionals, while the rest of the delta could be like New Jersey, supplementing Hong Kong,' Mr Lau said. But he noted there was uncertainty over how many people would treat the mainland as their first home and seldom return to Hong Kong. 'Knowing the category of these people, their number and why they choose to base their first homes in the mainland on a long-term basis and when they may come back would be very useful in future adjustment in land-use planning in Hong Kong,' Mr Lau said. The assistant director of the Centre of Urban Planning and Environmental Management at the University of Hong Kong, Professor Anthony Yeh, said there had always been a mobile population between Hong Kong and the mainland. 'Integration is inevitable, but in the process Hong Kong must be careful about the intake of mainlanders. It's such a small place,' he said.