During last decades, a lot of research has been aimed at mechanical characteristics improvements of materials and roads pavements, taking into account traffic requirements and service time for the initial construction. Besides, environmental impacts linked to roads are still seen today throughout regulation and focused on the use phase. Regulation imposes environmental impact studies (EIE) mainly in relation with nature and people protection. Then, studies are performed before roads construction, mainly devoted on roads location and on local effects of roads exploitation. On the other hand, since the 90’s, Life Cycle Analysis (LCA) has been considered by road civil engineers and public institutions workers as a possible way to improve road design at the international level. Life Cycle Analysis is a standardized environmental assessment method, which has been developed for products manufacturing improvement by USA chemical industries (SETAC). LCA proved to be well adapted for large numbers of manufactured products. It requires the use of a functional unit (FU) that accurately defines the product properties and functionalities to consider for a given service time. Moreover, it gives a relative assessment using a reference case, which has to be defined for each study. Hence, in France, a public reflection on national environmental stakes, has been conducted by the government since 2007. Concerning public works, it has led to the progressive incorporation of environmental criteria into public calls for tenders. In this context, the strategy of LCPC/now Ifsttar was to develop a tool –called ECORCE-, for LCA assessment and optimisation, in accordance to both road and LCA codes of practice. A set of steps and hypotheses for tool functionalities and implemented models is available, it is actually refined, including work on LCI data related to earthworks. The idea in this paper is to show pertinent indicators enabling the calculation of a series of eco-design parameters to better master the different effects on the environment; whereas the principles to minimise environmental loads are described as well. Both method and tool shall allow the professions concerned to deduce the best compromise between the different technical as well as environmental factors taken into account. In this paper the results mainly discuss earthworks, which are one of the main parts of construction works and overall common to all transport modes and apply to both urban and non urban areas, roads and railways using ECORCE. Typical results exhibited by two case studies are presented and the key parameters for eco design are discussed in order to determine possible improvements of considering environmental impacts during the design phase.
Eco-design for infrastructures in all transport modes