To effectively address carbon emissions both during construction and operation, major road infrastructure developments are looking for ways to integrate sustainability measures from the initial project planning phase. This approach leads to the development of transport assets that benefit the environment, support societal wellbeing, and are economically viable.

Responsible for the operation and maintenance of some of Denmark’s major infrastructure, Sund & Bælt appointed a joint venture (JV) between Arup and COWI (CAJV) to develop the preliminary design for the future approximately 10-km long Eastern Ring Road (Østlig Ringvej) in Copenhagen. The design will serve as the basis for an environmental impact assessment, potentially to be approved by the parliament via an act of construction.

To enhance the sustainability features of the project, Sund & Bælt in cooperation with the JV coordinated a larger advisory group with participants from private and public sector, academia, and non-governmental organisations to jointly define initiatives to reduce carbon emissions and generate social and economic benefits for residents.

The JV led a number of innovation workshops and related technical investigations to evaluate the viability, cost and climate impact of a large number of solutions, focused on integrating low-carbon materials and reducing the use of fossil energy sources during the construction of the Eastern Ring Road.

Improving connectivity between communities

Diverting traffic from downtown Copenhagen and surrounding neighbourhoods, the future Eastern Ring Road includes an immersed tunnel with four junctions. The project, connecting Copenhagen’s northern and southern motorway networks, aims to provide a new route for vehicles to relieve traffic through central Copenhagen and improve connectivity in the Øresund region, while supporting urban growth south of the city center.

Specialists from Arup and COWI are collaborating to design and plan this major transport asset, which represents a significant investment in Copenhagen’s infrastructure, reflecting Denmark’s commitment to sustainable and efficient urban transportation solutions.

The project connects Copenhagen’s northern and southern motorway networks. © Sund & Bælt

Facilitating innovation – a novel approach for sustainability

CAJV supported Sund & Bælt with organising innovation workshops over the past year, bringing together contractors, academia, and NGOs to help design a transport link which is good for society and the environment in the long-term. These workshops involved 55 experts from around 30 companies and other organisations who identified about 40 initiatives for reducing carbon emissions related to materials and construction activity, and for enhancing biodiversity and other environmental features.

Our specialists collected and analysed data and assessed each initiative for carbon saving potential, level of technical readiness, scalability, possible additional costs, and potential risks. For the cases that additional costs may be involved, CAJV has developed a method to rank initiatives according to the ratio of additional carbon savings to associated costs. This approach has enabled us to create a priority list of recommended initiatives for the design and construction planning of the Eastern Ring Road.

With today’s conventional choice of materials, the carbon emissions from concrete, in particular cement, and steel would have accounted for more than half of the total carbon footprint of the project. A large number of the initiatives have accordingly focused on ways to reduce both the quantities and emissions of these materials.

Another large portion of the carbon footprint comes from energy use during construction transport and site activities. Measures for decarbonisation include land-based and marine construction through electric and hybrid machinery, use of hybrid ships and alternative marine fuels, as well as measures to ensure adequate and effective electrical power supply for the land-based and marine construction plant.

Creating initiatives to protect the environment is also beneficial for biodiversity. For example, adopting hybrid ships can reduce underwater noise, which negatively affects marine life and is often linked to decreased species diversity.

Digital carbon accounting

The Arup and COWI JV has developed a digital Life Cycle Assessment tool to manage carbon emissions during the design phase of the Eastern Ring Road tunnel. Advising Sund & Bælt on the choice of building materials such as different types of concrete, the tool showcases the CO2 saving potential for different material options.

A 3D BIM model of the project was used to automate the assessment of materials and their properties, including emissions calculations and the verification of material properties against project specifications.

Sustainability as a design standard

Major infrastructure projects provide an arena for innovation where design teams can test and deliver novel solutions and technologies to support global carbon neutrality objectives, and grapple with climate change.

The Eastern Ring Road is one of a few projects to date that integrates sustainability at the very beginning of the design process. Establishing sustainability as one of the key design criteria means future large-scale infrastructure can progressively decrease its contributions to countries' carbon emissions, while promoting environmentally responsible practices.