The intensification of climate change, demonstrated by the increasing prevalence of heat waves and tropical nights, is becoming more apparent across the country. While the severity of climate change is widely recognized and various countermeasures have been implemented, most strategies still focus primarily on the energy and fuel sectors. In Seoul, for example, roads account for 23% of the city’s urban space but are often excluded from carbon emissions reduction policies.
Road infrastructure has a long life cycle and a complex composition; however, research in this area remains limited. Notably, the majority of carbon emissions associated with road infrastructure occur during the material phase, yet there is often a lack of data on raw material extraction and product manufacturing processes. Consequently, a standardized methodology for calculating carbon emissions from road infrastructure has yet to be established. To accurately assess carbon emissions in the realm of road facilities, it is essential to adopt a strategic approach that may include adjusting the life cycle scope or making assumptions for missing data. In this study, the focus was narrowed to asphalt pavement, concrete blocks, and curbstones. Additionally, the methodologies for calculating emissions from traditional materials and construction methods were reviewed, along with strategies for reducing carbon emissions, and comparisons of the emissions were made.
First, in the case of asphalt pavement, it was found that carbon emissions from the production of raw materials and mixture production account for 90% of the total emissions in the process. As a result, the potential for reducing carbon emissions through the use of recycled asphalt pavement (RAP) was examined. Additionally, the review included methods for lowering emissions by employing warm mix asphalt (WMA) and switching heating fuels to LPG/LNG. Other strategies for directly and indirectly reducing carbon emissions, such as generating renewable energy, creating green spaces, and enhancing quality control, were also considered.
Second, for paving blocks, a methodology for producing no-cement concrete blocks— which do not rely on cement as the primary material, unlike conventional paving blocks—was reviewed. The calculation of carbon emission reduction was based on the annual sidewalk pavement construction area in Seoul.
Lastly, due to the lack of examples for methodology calculations related to curbstones, the study examined an eco-friendly approach that replaces curbstones by recycling waste vinyl.
Priorities for emission reduction opportunities were established based on criteria such as significant carbon emission reductions, lower costs, and high potential for improvement within facilities or processes. The highest priority identified was extending the lifespan of road pavements through stringent quality control. This was followed by the use of Reclaimed Asphalt Pavement (RAP), Warm Mix Asphalt (WMA), fuel switching, the creation of green spaces, solar power generation, and the adoption of cement-free blocks.
To effectively reduce carbon emissions in the road infrastructure sector, proactive policy implementation, bold innovation, and continuous effort are essential. All stakeholders must be involved, including government entities, local authorities, producers, and construction companies. Furthermore, the Seoul Metropolitan Government should incorporate the road facilities sector into the reduction initiatives outlined in the Carbon Neutrality and Green Growth Master Plan (2024–2033) and manage reduction performance on an annual basis. To accomplish this, it is critical to implement policies that also address indirect emissions outside the workplace (Scope 3).