In year 2019, the transportation sector accounted for 23% of global CO2 emissions; emissions from the sector were expected to triple by the year 2030, possibly rising as a proportion of total emissions. Of all modes of travel, roads provide access to vital everyday services to large numbers of persons and thereby contribute to social development [1]. To address environmental concerns and to reduce emissions, the concept of “green transportation” was developed, alongside other measures such as the Net Zero Scenario, shared mobility services, and the integration of renewable energy technologies, among others. These measures have shown promising results for sustainable transportation through alleviating traffic congestion and through reducing carbon emissions. Yet, there is a need for solutions that integrate management measures with new technologies from the planning stage of road development through to achieving sustainable road transportation.
What are Green Roads?
One of the sustainable approaches to minimizing the ecological impact throughout the lifecycle of road infrastructure is ‘Green Roads’. Green roads, often referred to as green highways, were first implemented in the USA through the alliance of public-private organizations under the name ‘Green Highways Partnership (GHP)’ in 2006. The program identified and implemented significant features of green highways, such as incorporating the use of sustainable materials, energy-efficient solutions, low material, low energy, and low maintenance technologies, etc., and developed a ‘Green Roads’ rating system to evaluate the performance of roadways and highways [2, 3]. However, there is no single, universally agreed-upon definition for ‘green roads’; instead, the concept is defined in broader terms according to the nature of the innovative techniques and region-specific approaches employed to mitigate climate impacts.
Many governments worldwide have initiated efforts to explore different techniques and innovations to achieve sustainability and to reduce carbon emissions from road construction and maintenance. In Nepal, the Green Road Concept (GRCO), developed over the past two decades, integrated conservation-oriented, labor-based technologies to expand rural road access while generating income by engaging local communities in hilly regions [4]. Further, the Green Highway (Sweden–Norway) project (2020), stretching 450 km from Trondheim (Norway) to Sundsvall (Sweden), operates as a fossil-free transport corridor powered by renewable energy and promotes cross-boundary collaboration between cities and municipalities, [5].
Evidently, the definition of a “Green Road” is context-specific. Over time, the core idea of ‘Green Road’ has expanded to focus on water management and conservation. Traditionally, roads and water generally considered incompatible, as water can damage road infrastructure, leading to a long-standing belief that blacktop surfaces impede rainwater percolation, contribute to declining groundwater levels, and impact local ecosystems negatively [6]. However, this view can be addressed through some intentional engineering design, using cross-sectional slope (“camber”) and longitudinal gradient along road lines to channel rainwater through integrated drainage systems to recharge structures efficiently. Additionally, emerging techniques like nature-based solutions (NBS) are integrated into transportation infrastructure to manage water, recharge groundwater, and control run-offs [7]. The concept of “Green Roads for Water”, developed in 2019, reframes the long-standing critique by using roadways as a tool to manage water resources by incorporating groundwater rejuvenation, landscape restoration, agricultural development, and disaster risk reduction, thus linking roads and water management to climate adaptation and ultimately to community resilience [8]. An integrated approach with engineering and design, where appropriate, can contribute to large-scale water management and water security and act as disaster protection.
Green Roads in India
India introduced the ‘Green Highway Policy’ in 2015 to reduce air pollution by planting trees and shrubs along highway corridors to create natural sinks and to control soil-erosion [9]. With this as a foundation, in 2020, the Indian government collaborated with the World Bank to initiate the Green National Highway Corridors Project, providing all-weather connectivity spanning 781 km across four states of the country. The project incorporated locally procured recycled materials and integrated green technologies and bioengineering solutions (hydro-seeding, coir mats, etc.) primarily in hilly regions, to reduce carbon emissions and to conserve upon natural resources, [10].
Additionally, to minimize plastic waste and to improve the durability of roads, Indian states such as Tamil Nadu and Maharashtra have used recycled plastics to lay roads. Over 100,000 km of roads have been built in India with the same approach. On the Delhi-Meerut Expressway, for instance, solar-powered toll plazas and light poles were installed to reduce the load on grid networks. Likewise, along the National Highway 44 corridor through the Pench Tiger Reserve, several mitigation measures, including eco-ducts and underpasses, and the introduction of native and drought-resistant plant species, were built to provide safe wildlife crossings and to support local ecosystems. The Delhi–Mumbai Expressway includes more than 2,000 rainwater harvesting structures to ensure a water-sensitive design, [11].
The [Green] Road Ahead
Although the green road concept has garnered support globally, several challenges remain. These add-on projects bring substantial financial implications, and many countries lack the technical skills needed for green construction practices; therefore, such projects experience delays in implementation, [12]. In addition, literature highlights limitations such as inadequate and unclear policies/frameworks, hesitation among stakeholders in switching to low-carbon initiatives such as sustainable materials, design optimization, and energy-efficient practices, lower priority from the governments, and cultural barriers [13, 14]. However, a few initiatives were taken to streamline the concept of green roads. In 2021, the World Bank published guidelines for road infrastructure in support of water management and climate resilience, along with successful case studies [15]. Similarly, the Asian Development Bank (ADB) has developed a ‘Green Roads Toolkit’ (2024) to help developers and policymakers by providing practical solutions for achieving environment-friendly road networks [16].
As cities grow, there will be a need to integrate road planning, development, and maintenance to ensure sustainability. But the future of green roads may potentially go beyond merely eco-friendly thoroughfares. Emerging technologies such as artificial intelligence (AI) are poised to transform road and urban infrastructure. As per the KPMG report (2025), roads will become self-reliant networks driven by artificial intelligence to monitor and analyze real-time data, guide and re-route traffic, identify accident hotspots, automate toll collection, interlink mobility and renewable energy micro-grids, and to assist in sustainable construction by optimizing materials, designs, and more [17]. These smart technologies can serve as a base for net-zero cities and climate-smart transport corridors, thereby redefining the notion of urban mobility and climate adaptation. Ultimately, green roads not only connect different geographical locations but also foster harmony between the commuters and nature.
References
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[2] Green Highways: Partnering to Build More Environmentally Sustainable Roadways - FHWA-HRT-08-012 - Focus | Federal Highway Administration. www.fhwa.dot.gov, Apr. 2008, https://www.fhwa.dot.gov/publications/focus/08apr/01.cfm Accessed 19 Oct. 2025.
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[12] Chau, Hing-Wah, et al. “Key Barriers and Challenges to Green Infrastructure Implementation: Policy Insights from the Melbourne Case.” Land, vol. 14, no. 5, 29 Apr. 2025, pp. 961–961, https://doi.org/10.3390/land14050961
[13] Sonero Sourn, et al. “Barriers to Green Implementation in Highway Construction in Cambodia: Identification of Root Causes.” International Journal of Sustainable Development and Planning, vol. 17, no. 3, 2 June 2022, pp. 715–725. Google Scholar, https://doi.org/10.18280/ijsdp.170302. Accessed 23 Mar. 2025.
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[15] Van Steenbergen, F. W. M., Arroyo Arroyo, F., Deligianni, A., Hulluka, T. A., Rao, K. S., &Woldemariam, K. W. (2021, June 15). Green Roads for Water: Guidelines for Road Infrastructure in Support of Water Management and Climate Resilience. World Bank Group; https://documents.worldbank.org/en/publication/documents-reports/documentdetail/102951623742853259/green-roads-for-water-guidelines-for-road-infrastructure-in-support-of-water-management-and-climate-resilience
[16] Green Roads Tool Kit | ADB Data Library | Asian Development Bank. (2024, May 10). Adb.org. https://data.adb.org/dataset/green-roads-toolkit
[17] AI-Powered Road Infrastructure Transformation - Roads 2047. KPMG, 3 Sept. 2025, https://kpmg.com/in/en/insights/2025/09/ai-powered-road-infrastructure-transformation-roads-2047.html. Accessed 19 Oct. 2025.