A team of architecture professors and students have come up with an imaginative plan to create more green space in the city, starting with the neighbourhood of the West Kowloon Cultural District. The study, led by Cheung Kwok-pun, associate professor of architecture at the University of Hong Kong, advocates the concept of vertical development on highway junctions. Existing highways take up a lot of space, particularly seafront strips of land, and often cut through urban blocks making them far away from each other, Cheung said. 'Developing the spaces above and around them wisely could be an efficient way to use urban land and a way to cope with the expanding population,' he said. The study proposes what it calls 'vertical sustainable connection of four uses' - a multi-storey basement below the highway for commercial and cultural use; the highway; raised parks on decks seven metres above the highway; and low or medium-rise residential development on the elevated decks. The team has identified 30 highway junctions across the city which, Cheung claimed, with such vertical development would free 180 hectares of land. The West Kowloon Highway, for example, could be built over with low or medium-rise housing. The space designated for housing within the arts hub could then be freed to accommodate more arts facilities and even a stadium. Cheung said the plan was 'preliminary' and no cost specifics were available, but he hoped it could stimulate the thinking of government planners. 'Existing planning practices tend to treat every district separately and often lack an integrated approach for the whole urban area,' he said.