The country's efforts to build a comprehensive public transport system have seen rapid progress in the last four years, the statistics bureau said.

In 2006, investment in railway construction in China reached 155 billion yuan, up 149 percent from 2002 and with an annual average growth rate of 20.4 percent, according to a National Bureau of Statistics (NBS) report released on Friday.

By the end of 2006, China's rail system was the world's third longest, with 70,000km in operation. The country's railways have been extended by 7.2 percent, or 5,000km, since 2002.

Expressway and highway systems have also been enhanced in recent years. By the end of 2006, the country had 45,000km of expressways in service, an increase of 80.4 percent from 2002.

Expanded highway construction in rural areas has also helped boost rural economic development and improve the living environment of rural residents. In rural areas, the highway system stretched 3.02millionkm by 2006, while 86.4 percent of the country's counties are now linked to the national highway system. The NBS report said 16 provinces have highway mileage of more than 100,000km in rural areas.

The aviation network is also growing more quickly than ever before, according to the NBS report. Air routes were expanded in the 2002-06 period, which saw aggregate airline mileage for passenger transport increase 29.1 percent to 2.11 millionkm, while the total number of air routes increased 13.6 percent to 1,336. There were 1,614 civil aircrafts in operation, up 45.1 percent from 2002.

Ma Ying, an aviation analyst at Haitong Securities, said the domestic aviation industry has seen unprecedented growth momentum in the past few months.

"The fast-growing aviation industry will bring more convenience to domestic passengers and the increasing demand for global travel will boost the continuous development of the sector in the following years," Ma said.

There were 159 million civil airline passengers in the country in 2006, up 85.8 percent from 2002, according to the NBS report.

In the first six months of the year, the customer and seat ratio of the whole industry averaged 73.9 percent, up 1.6 percentage points from a year earlier. Combined turnover from the main business in the industry reached 85.9 billion yuan, up 19 percent. Aggregate profit was 1.5 billion yuan, an increase of 3.9 billion yuan from last year's loss.

Outgoing airline passengers from China are increasing at a faster rate than those on domestic flights. In July, passenger numbers on international flights increased 20 percent year-on-year compared with a 15 percent gain on domestic flights.

The country's shipping capacity has also expanded in recent years. In 2006, cargo transported by major seaports amounted to 4.6 billion tons, up 105.8 percent from 2002.