Green infrastructure have been widely spread to counter the negative effects of urbanization. However, their economic feasibility still generates discussion between researchers, investors and suppliers, leading to the need for more accurate and case-specific cost-benefit analysis. This study pretends to analyze the economic feasibility of greening transport infrastructures, in particular road tunnels. The proposed methodology includes the life-cycle costs and benefits of green systems. Its incremental approach considers economic appraisal components (financial, economic and socioenvironmental) and transport infrastructures dimensions (infrastructure, user and surroundings). This study simulates five green case studies in underground passages of a roadway with high traffic intensity in Lisbon, Portugal. Four out of five scenarios are economically feasible using a life-cycle of 40–50 years and a discount rate of 4,8 %. The final net present values range from 33.961 to 5.079.356 €. Discount and inflation rates, financial costs, reduction of the noise inside the tunnels, creation of new functional areas and aesthetical improvements have great significant impact on projects’ economic return.

绿色基础设施已经广泛传播，以应对城市化的负面影响。但是，它们的经济可行性仍引起研究人员，投资者和供应商之间的讨论，导致需要进行更准确和针对具体情况的成本效益分析。这项研究假装分析了绿化交通基础设施特别是公路隧道的经济可行性。拟议的方法包括绿色系统的生命周期成本和收益。其增量方法考虑了经济评估的组成部分（财务，经济和社会环境）和运输基础设施的规模（基础设施，用户和周围环境）。这项研究模拟了葡萄牙里斯本高交通强度的地下通道中的五个绿色案例研究。使用40–50年的生命周期和4.8％的折现率，五分之四的方案在经济上都是可行的。最终的净现值范围是33.961到5.079.356€。折扣和通货膨胀率，财务成本，减少隧道内部的噪音，创建新的功能区域以及美学上的改进对项目的经济回报产生重大影响。