The cost has increased due to higher bid prices, and increase in cost of land acquisition, resettlement and rehabilitation and other pre-construction activities, the government said.
The projects are already taken up for implementation and 429 kms has been completed. They comprise development of 1,120 kms of National Highways in the States of Karnataka, Odisha, Bihar, Rajasthan and West Bengal.
The civil works are expected to be completed by July, 2019 and maintenance works are expected to be completed by July, 2024, the government said.
The project will ensure safe, fast and all weather movement of traffic on the proposed National Highways mostly located in backward regions thereby improving socio economic development.