Blacktown is the best performer of 15 employment clusters in commute times to work. Credit:Wade Laube The study by the University of NSW of a typical weekday morning shows second place for speed of travel is to the site of the new Northern Beaches Hospital at Frenchs Forest, which had 69 per cent of people get there within half an hour. It was followed closely behind by Liverpool at 67 per cent. However, more people got to Liverpool within 45 minutes than Frenchs Forest. In contrast, only 27 per cent of people travelling to Sydney Olympic Park got there within half an hour, while for North Sydney it was 37 per cent and the CBD 39 per cent. While 44 per cent of people travelled to Randwick in the city's east within 30 minutes, the home of the UNSW and several large hospitals had the highest proportion of people taking an hour or more at 36 per cent.

Chris Pettit, the associate director of UNSW's City Futures Research Centre, said he was surprised to find many centres in western Sydney tended to have a high proportion of people travel to them within 30 minutes. "Those areas in western Sydney, on this particular metric, are performing better than eastern suburbs areas," he said. Professor Pettit said the longer trip times to destinations in eastern parts of Sydney was partly due to greater urban density, which increased congestion on major thoroughfares. Higher property prices in the eastern suburbs also curbed people's ability to live close to where they worked. "They are just priced out of the market, so we are seeing people live out a lot further because that's all the can afford," he said.

In contrast, Professor Pettit said areas such as Liverpool and Blacktown were less densely populated and more affordable to live. "People are more likely to be living around Blacktown. So the distance from home to work is a lot less," he said. However, the push for Parramatta to become Sydney's second CBD, and an "aerotropolis" further west around the planned new airport at Badgerys Creek, would significantly increase population and pressure on the transport network. "We need to ... make sure we don't lose the accessibility that we have out west in some of these employment centres," he said.

"There is a real opportunity to use this data to try to at least maintain, if not improve, the accessibility of those western employment centres." Professor Pettit said greater investment in public transport, including cycle and walking paths, was needed in these areas to ensure they kept pace with the surge in population and the push to attract more businesses. The researchers examined trips from anywhere on the public transport network to the employment centres during the morning peak on March 16 last year, a day without any major disruptions from weather or major incidents. Travel times on public transport to Sydney's central business district performed reasonably well because "through the hub-and-spokes model all roads lead to Rome". About 69 per cent of trips to the CBD were with 45 minutes, while only 12 per cent of commuters took longer than an hour.

The CBD has more three times the number of journeys on a typical workday than the next biggest destination of Chatswood. The study was conducted to inform the district plan for the Greater Sydney Commission, which selected the key centres it was focusing on from the perspective of the so-called 30-minute city.