NHAI and the Department of Fertilizers are set to conduct field trials on National Highway projects using Phosphor-Gypsum, a by-product of fertilizer production, to promote ecologically sustainable highway infrastructure. A road constructed using Phosphor-Gypsum by an Indian fertilizer company was evaluated by CRRI and accredited by the Indian Road Congress for three years.
NHAI is also promoting the use of waste plastic and Fly Ash in road construction to reduce the carbon footprint, increase durability and make construction more economical. One kilometre of 4-lane highway construction helps dispose of around seven tons of plastic waste. The Eastern Peripheral Expressway used 1.2 crore cubic meters of fly-ash in its construction.