The conversation around decarbonising road transportation often focuses narrowly on a single solution, like electric vehicles. But a truly effective public strategy for reducing the impacts associated with transport requires a much broader, 360-degree vision. 

The facts are clear: the transport industry accounts for 13.7% (2021, source: WRI) of GHG emissions, while infrastructure construction contributes to 1% to 2% of GHG emissions (source: ORIS). To make a lasting impact, we must reimagine user mobility as an interconnected, multimodal system and challenge the status quo from the very beginning of a project.

This means rethinking how we utilise existing spaces and design new construction to create more efficient and sustainable road networks. Real change isn't built on good intentions; it's built on four inseparable pillars, each with concrete examples that prove their effectiveness.

1. Re-think Your Projects: Early-Phase Optimisation for Transport Infrastructure

A key part of a sustainable approach is to optimise existing infrastructure and question whether every new project is truly vital. This proactive strategy not only saves on material and construction emissions, but also on the long-term environmental impact of the infrastructure itself.

In 2021, Wales demonstrated bold leadership by committing to reducing emissions from road transport. Following a comprehensive review published in the report, "The Future of Road Investment in Wales", new road projects are now only approved if they meet specific conditions. These include prohibiting an increase in traffic speed, avoiding new capacity for private vehicles (if a new lane is added, it must be dedicated to public transport, soft mobility, or carpooling), and minimising construction-phase carbon emissions. This policy directly acknowledges a fundamental truth: more lanes do not solve traffic congestion.

Similarly, renovation projects must now systematically question their purpose and propose concrete solutions, such as:

• • Establishing carpooling lanes and promoting soft mobility.
  • Prioritising the connection and use of public transport, which means reserving express bus lanes or investing in projects that integrate different transit networks.

This is exemplified by the 2020 redevelopment project of the M6 and M7 motorways near Lyon, France. The project involved:

• • Declassifying the motorway to a metropolitan road, reducing the speed from 110km/h to 70km/h.
  • Creating a fourth lane dedicated to public transport.
  • Implementing a traffic lane reserved for carpooling.
  • Building new carpooling areas and park-and-ride lots.
    
    

This ambitious rehabilitation aimed to improve traffic flow while encouraging a reduction in the number of cars by focusing on modal shift. These cases illustrate a multi-criteria optimisation strategy founded on reuse, prospective analysis, and a commitment to reducing impacts across the entire infrastructure lifecycle. This is what it means to design for resilience and sustainability.

2. Performance in Construction: GHG Reduction Through Procurement Standards

To truly reduce GHGs, they must first be measured and then planned for. We must first measure emissions to mitigate and plan effectively. The goal is to make a tangible, measurable impact on every project.

National Highways in the UK has demonstrated how to use public procurement as a powerful lever for change. Their public strategy for mitigating the impacts associated with transport centres on two main levers: mandating the systematic measurement of projected GHG emissions during the study phase and establishing clear procurement rules for bids. They have introduced strengthened evaluation criteria that focus on the concrete reduction of emissions from materials, transport, and project execution. This involves embedding circularity into every project, with a measurable impact. In 2021, National Highways recognised a project on the A590 J36 to Brettargh Holt that achieved a 55% reduction in emissions at the construction stage, with the remainder offset to reach carbon neutrality.

3. Social Equity: a Just Transition for Road Transportation

A sustainable transition must be a just one. Policies mustn't exclude vulnerable citizens or small businesses.

The Scottish government provides a prime example of how to develop an inclusive public strategy for reducing the impacts associated with transport. They have increased funding to support vehicle changes for Low Emission Zones (LEZs). This fund aims to accelerate the renewal of the car fleet and popularise public transport and soft mobility. While LEZs are essential for improving air quality, they can raise concerns about social equity. By strengthening the "Low Emission Zone Support Fund," the Scottish government wants to support low-income individuals and small businesses, preventing their exclusion. The fund will finance the renewal of their vehicles, the purchase of soft mobility solutions such as e-bikes and cargo bikes, and will also focus on adapting public transport fares.

4. Support Usage Change: Accelerating the Transition from Fossil Fuels

The elephant in the room is that out of the 13.7% of global GHG emissions, 88% are linked to road transportation (Passenger & Freight) and the combustion of fossil fuels. To truly transform the transportation sector, we must accelerate the transition away from fossil energy sources.

In 2023, the European Union made a bold decision to stop the registration of new, non-electric vehicles from 2035. This sends a clear, long-term signal to manufacturers, giving them over a decade to prepare for this significant market shift. This policy provides not only a definitive timeline for the industry to realign its strategies and accelerate the production of zero-emission vehicles but also an additional push for the European motor vehicle manufacturers to be ready and competitive in regard to the constant growth of EV manufacturers outside of Europe.

This proactive approach for energy shift is also being adopted in other parts of the world. In Nepal, successive governments have implemented an ambitious policy to reduce their dependence on oil by investing heavily in renewable hydroelectric energy. The country has transitioned from an electricity importer to a net exporter, with nearly 95% of its production coming from hydro sources. This shift enabled Nepal to set ambitious and successful goals for replacing fossil fuel vehicles with electric vehicles, to have 73% of imported and registered cars be EVs by 2025.

Conclusion

A truly effective decarbonization strategy is built on a foundation of these four pillars: sober demand, optimisation, performance, and social equity. Linking measurable carbon requirements to public policy and citizen support is no longer a constraint; it's the engine for a durable, accepted, and innovative future for everyone. It is the core of a mission-driven approach that helps build a more resilient and sustainable world.