BEIJING: China's investment on development of roads, railways airports and waterways is expected to hit $409 billion by the end of the year as the Communist Nation continues to rely on the sector to sustain growth.Fixed asset investment on China's transport infrastructure , including roads, railways, airports and waterways, are expected to hit 2. 5 trillion yuan ($409 billion) this year, Minister of Transport Yang Chuantang said.Transportation played an important role in China's efforts to stabilise economic growth by speeding up investment on infrastructure construction, Yang said at a national transport work conference held in Beijing yesterday.Yang said the investment this year is expected to increase road network by 93,800 kms including 7,450 km expressways.Meanwhile, 2.30 lakh roads in the countryside roads are to be renovated in the year, the media reported.Total investment on railways are to hit 800 billion yuan ($133 billion) this year, which has increased railway mileage by 8,000 km, Yang said.Eight new airports have been built, while 631 berths are built or reinforced with the investment this year.Yang predicted that the total passenger and freight volumes via the nation's transport system , including roads, railways, airports and waterways, will increase 3.7 per cent and 7.2 per cent year on year respectively.For long infrastructure remained a key driver of economic growth in China and it continues to be so as a slew of recent economic indicators showed the world's second largest economy is going through a rough patch.Economic growth has slipped to 7.3 per cent in the third quarter from a year earlier, and November's weak manufacturing, factory and investment figures suggest annual growth may not hit the official target of 7.5 per cent.The weak data has prompted economists and research institutes to downgrade forecasts for China's economic growth this year and predicted China may lower its annual growth target to around 7 per cent at the national legislative session in March.