Automobile manufacturing sector shows tremendous jump: Nath

India's Road and Transport minister Kamal Nath on Wednesday said that the high trajectory growth in manufacturing sector, especially automobiles, that India has witnessed, would boost an ambitious plan to build roads. India has the world's second largest road network at 3.4 million km. And the national highway network, which doubled in size between 1997 and 2007, stands at an impressive 70,000 km.