Bottom ash from waste incineration is being used in road construction to save resources. A study looked at how this helps reduce carbon emissions. They found that adding bottom ash to asphalt reduces carbon emissions the most, but increases energy consumption. For other materials like concrete, adding bottom ash decreases carbon emissions. The best carbon reduction is achieved by adding 20% bottom ash to asphalt and 30% to cement-stabilized crushed stone mixtures. This helps reduce carbon emissions in urban road construction.