Congestion problem could crush America's ports within a few years from now, so say experts who have therefore urged the authorities concerned in the US to spend more on its clogged transport infrastructure and to boost productivity at its ports. While China is investing billions of dollars on new infrastructure development to support its burgeoning trade, the ageing US transport system is failing to keep pace. "The question is not if, but when, the system becomes congested", observes one expert, adding, "all components of the US supply chain are stressed." Another expert has been quoted as saying that serious congestion problem will hit the US ports by 2008 as the productivity in US ports is half that of many Asian ports, particularly Singapore and Hong Kong. The year 2004 was particularly bad with clogged inter-modal rail networks and up to 100 vessels forced to wait at anchor for berths in southern Californian ports, and a severe labour shortage dealing a heavy blow to marine terminal productivity. The situation in 2005 improved a little, thanks to special initiative, hiring thousands of extra workers, mooted to tackle the problem but such a measure would not work for long. The system would encounter renewed pressure in the coming years as the existing infrastructure would reach the saturation point. Worse, as the experts warn, the existing ports would be unable to build their way out of danger because of the non-availability of suitable waterfront land for development and environmental restrictions on expansion.