The article discusses a new method to evaluate the environmental impact of building bridges. The researchers created a model that looks at how much energy is used, pollutants are released, and resources are consumed during the bridge's life cycle. They tested the model on a highway bridge and found that the biggest environmental impact comes from making and processing the materials, followed by building the bridge and then maintaining it. This new approach can help reduce the environmental impact of bridge construction and can be used for other types of construction projects worldwide.