NEW DELHI: To strengthen the country's road infrastructure, the government will convert eight National Highways, including Delhi-Jaipur, Delhi-Chandigarh and Delhi- Agra sections, into world-class express highways, Parliament was informed today.The stretches approved for upgradation into expressways include 249 km Delhi-Chandigarh section of NH-1 and NH-22; 334 km of Bangalore-Chennai section of NH-4; 261 km of Delhi- Jaipur section of NH-8, and 277 km Kolkata-Dhanbad stretch of NH-2, Minister of state for Road Transport and Highways Pon Radhakrishnan said in reply to Lok Sabha today. The National Highways to be upgraded also include 66 km Delhi-Meerut section of NH-58; 200 km of Delhi-Agra section of NH-2 and 135 km length of Eastern Peripheral Expressway, he said."Feasibility study of above projects are in different stages. The work shall be taken up after finalisation of feasibility study and completion of land acquisition activity," he said.The Minister said, " Government of India had earlier approved a plan for constructing 1,000 km of expressways under NHDP PHASE - VI at a cost of Rs 16,680 crore on DBFOT (design, build, finance , operate and transfer basis."In a separate reply to the Lower House , he also said that construction of a six-lane expressway is envisaged at centre with 4-lane highways on both sides from Delhi/Uttar Pradesh border section of NH-24 for which bids have been invited on hybrid annuity mode.Last month, Road Transport and Highways Minister Nitin Gadkari said work on 10 expressway projects will start soon and once completed they will not only reduce travel time between major cities but would also contribute significantly towards the economic growth."All these express highways are going to be world class matching the quality and specifications in advanced nations and once completed would result in huge savings in fuel cost," he had said.He has said most of the projects will be concrete cement expressways.An express highway is a controlled-access highways, mostly 6-lane or above, where entrance and exit is controlled by the use of slip roads (ramps) that are incorporated into the design of the highway.The Indian road network of 33 lakh km is the second largest in the world and consists of 92,851 kms of National Highways, which constitute only 1.7 per cent of the road network but carry about 40 per cent of the total road traffic.