Key challenges and opportunities in transitioning towards road bridges with reduced carbon emissions - Perspectives in Switzerland

The construction sector is a major contributor to CO2 emissions, responsible for approximately 37% of global and 23% of Switzerland’s total emissions. Addressing this substantial carbon footprint requires innovative and sustainable materials, advanced construction techniques, and comprehensive stakeholder engagement. This paper discusses the key challenges and opportunities in transitioning towards reduced carbon emissions within the construction sector, focusing on the Swiss industry and road bridges as a case study. An extensive dataset of Swiss road bridge infrastructure is assessed herein to understand the current state in Switzerland. An engineering-oriented critical review of high-performance materials such as non-metallic reinforcements, lower impact concrete mixtures and timber products is made in comparison to established construction materials. Circular principles and design for disassembly are explored as strategies for reducing environmental impact. This paper identifies the critical role of availability of early-stage information regarding environmental impact, standardization of emerging materials and techniques, and stakeholder engagement in driving the construction sector towards practices with reduced carbon emissions. Emphasis is put on the requirements and alternatives for achieving reduced carbon emissions in newly constructed bridges, while the potential for extending the service life of existing bridges and its importance for achieving net-zero infrastructure goals is acknowledged but not explored.