NHAI Launches India’s First Satellite-Based Green Cover Index for Highways

In a major step toward environmentally sustainable infrastructure, the National Highways Authority of India (NHAI) has released the first-ever Annual Report on the National Highways Green Cover Index (NH-GCI) 2025–26, providing a scientific assessment of vegetation cover along the country's highway network.

The report, prepared in collaboration with the National Remote Sensing Centre (NRSC) of the Indian Space Research Organisation (ISRO), introduces a technology-driven method to measure green cover along National Highways using satellite-based data.

Satellite Technology Tracks Highway Green Cover

The NH-GCI initiative uses high-resolution satellite sensors to detect chlorophyll content, enabling accurate measurement of vegetation along the Right of Way (RoW) on both sides of National Highways.

The index measures the proportion of green cover within the RoW and reports it as a percentage value at a one-kilometre interval, offering a detailed and quantitative view of plantation coverage across the highway network.

Officials say this method allows objective monitoring of vegetation growth and plantation success, replacing earlier manual and sample-based approaches.

30,000 km of Highways Assessed

In its first assessment cycle, the report covers approximately 30,000 kilometres of National Highways across 24 states, based on data collected between July and December 2024.

The results provide the first large-scale, satellite-based evaluation of roadside vegetation along India's major transport corridors.

Future annual assessments will track year-on-year changes in green cover, helping authorities monitor progress and identify areas requiring further plantation efforts.

ISRO Partnership Strengthens Environmental Monitoring

The NH-GCI initiative is being implemented under a three-year Memorandum of Understanding (MoU) signed in January 2024 between NHAI and NRSC-ISRO.

The partnership combines NHAI's infrastructure management expertise with ISRO's advanced remote sensing capabilities, enabling reliable and cost-effective environmental monitoring across thousands of kilometres of highways.

According to officials, the approach provides a robust, scalable and time-efficient mechanism for estimating vegetation coverage at the national level.

Tool for Better Plantation Management

The NH-GCI report will help authorities:

• Track green cover growth along highways

• Identify stretches requiring additional plantation

• Compare environmental performance across regions

• Support data-driven planning for highway greening initiatives

The index will also enable ranking and benchmarking of highway stretches, encouraging improved plantation management and maintenance practices.

Supporting Sustainable Infrastructure

The initiative reflects NHAI's broader commitment to integrating environmental sustainability into infrastructure development.

India has significantly expanded its highway network in recent years, and authorities say monitoring green cover will help ensure that infrastructure growth aligns with climate goals, biodiversity protection and ecological restoration efforts.

By leveraging space technology for environmental monitoring, the NH-GCI marks an important step in building greener and more sustainable transport corridors across the country.

The full report is available on the NHAI website.