The current transport system is not sustainable because of its high consumption of finite resources (mainly oil) and its impact on the environment (air quality, global warming, etc.). The design phase of the transport infrastructure has to be reconsidered in order to take into account these environmental burdens. Very recently, a methodology called Sloop (Slope Optimization) has been proposed to optimize the road longitudinal profile according to either an energy consumption or a Global Warming Potential (GWP) criterion calculated for construction and use phases. However, this optimization requires a high computation effort. It is a severe limitation to deploy this application to significant road project . The purpose of this paper is to propose a tailor-made optimization process which improves significantly this methodology. For the construction phase assessment, the methodology is based on a model of earthworks which computes the differences of geometry between the natural terrain and the road longitudinal profile. The use phase is assessed by simulating the traffic. Traffic simulations are based on vehicle dynamic models validated with real experiments. Starting from an initial longitudinal profile proposed by road designers, our algorithm finds a better profile in terms of Energy or GWP. The degrees of freedom of the optimization problem are mainly the road slopes and secondly the radii of the circles which connect them. The main constrain is the connection of the profile with the existing road. The optimization is complex due to the important number of degrees of freedom and the computation cost of the use phase assessment. It is the reason why, we developed a specific algorithm based on the Sequential Quadratic Programming Method (SQP) with suited computations of the linear approximation.