Some Australian cities have seen more people using public transport since 2000, while others have had less growth or even declines. This isn't just because of things like gas prices or traffic. It's also because of how businesses are clustering together in certain areas, which helps them be more productive. Industries that rely on knowledge and information are growing, and they're choosing to set up shop in places where they can work closely with other similar businesses. These areas often have good public transport, which is why some cities are seeing more people using buses and trains.