The National Highways Authority of India (NHAI) on Monday released the first National Highway Green Cover Index (NH-GCI), establishing a baseline for measuring vegetation along the country’s highway network using satellite-based assessment.
Subsequent annual cycles will track annual changes along the same stretches of the highway, enabling monitoring of improvements in roadside vegetation over time, NHAI said in a statement.
The index was prepared in coordination with the National Remote Sensing Center (NRSC) of the Indian Space Research Organization (ISRO) after the signing of a memorandum of understanding between the two agencies in January 2024 to establish a scientific and quantitative framework for assessing farms along national highways.
The index uses high-resolution satellite sensors to detect chlorophyll content along highway corridors, enabling an estimate of right-of-way vegetation on both sides of the road.
The first evaluation cycle covered about 30,000 km of national highways across 24 states for the period between July and December 2024.
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According to NHAI, the index is a technology-based approach to estimate green cover at the aggregate level along highways and can help identify stretches with relatively low vegetation levels where plantation management may require attention. The framework also allows comparison and classification of highway sections based on green cover. She said the use of satellite data provides a cost-effective and time-saving way to monitor vegetation along the expanding national highway network.
The release of the NH-GCI report follows NHAI’s publication of its Sustainability Report in July 2025, which outlined the agency’s sustainability initiatives and environmental performance across its highway development site and operations.
