NEW DELHI: India has over one lakh kilometres of national highways (NHs), but there is no scientific road network pattern and drivers can't take a straight road to reach from one place to the other. To address this, NHAI has prepared a grid of 27 horizontal and vertical national highway corridors at a distance of every 250 km crisscrossing the country.All these stretches will be of four lanes and will provide more road space for seamless transport. The total length of these corridors, including ones such as Kanyakumari to Srinagar, Porbandar to Kolkata , Surat to Paradip Port, Rameswaram to Dehradun and Mangalore Port to Chennai Port, is about 36,600 km. Out of this, about 30,100 km are already NHs. But only 18,800 km of them are of four-lanes.“The rest are either single or two lanes and we have missing NH link of about 6,500 km, which are either state highways or major district roads. These stretches need to be converted into NHs and widened to four lanes for smooth travel,“ said an official. Sources said going by the standard costing, the government will have to invest about Rs 25,000 crore for completing four-laning of the routes.The preparation of the grids will help the government re-designate the NHs for easy identification. For example, all even number NH grids can be identified for roads connecting east to west and odd number for corridors joining north end to south.“The grids will be important as the government is focusing on integrated transportation network. These grids will connect all major ports, which will help in quick evacuation and transport of cargo from one end to the other,“ another official said.Sources said highway ministry has shared this plan with states and sought their views. “We want to be sure the states have not awarded or planned roads on PPP mode that are parallel to the identified routes,“ a source said. TOI has learnt that NHAI had made a detailed presentation to highway minister Nitin Gadakri in March. The proposed NH grid shall not only improve connectivity in each region and state capital but will also provide highway link to 12 major ports, 45 out of 53 million plus cities and 26 state capitals besides providing connectivity to major tourist and religious places.The NHAI said planning for horizontal and vertical grid network was done keeping the concept of parallels to the existing north-south and east-west corridor alignments. These parallels are spread across the country , uniformly and thereby providing connectivity to every region.“The existing NH network depicts unbalanced network and even creates problem in numbering NHs systematically from road users' perspective.The current approach has focused on state-level planning,“ said an official.During UPA-2 , then highway minister Kamal Nath had made an effort to re-designate the existing NHs but it did not bear fruit.