Ways to make roads stiffer are already available and could improve heavy vehicles’ gas mileage at little to no cost, thus reducing their carbon emissions. Making 10% of U.S. road surfaces stiffer would reduce a yearly total of 440 megatons of CO2 equivalent emissions.
Source: AzariJafari, H., Gregory, J., & Kirchain, R. Potential Contribution of Deflection-Induced Fuel Consumption to U.S. Greenhouse Gas Emissions. Transportation Research Record, 2020.