Évaluation environnementale du PDU nantais 2000-2010 à partir des simulations numériques des scénarios alternatifs du programme Eval-PDU

The pluridisciplinary research program Eval-PDU proposed a chaining structure of physically-based, numerical models computing multimodal traffics on the networks, energy consumptions, greenhouse gas emissions, atmospheric pollutant concentrations, their health impacts, noise levels, and their consequences on real estate values. These models are linked by a common spatial data infrastructure that ensures data management from one modelling stage to the others and provides computation algorithms of original synthetic indicators by putting in relation simulation results and data of different natures. The method has been tested to evaluate the environmental impacts of the 2000-2010 transportation master plan (PDU) of Nantes Metropole, based on numerical simulations of the real situations of 2002 and 2008 on the one hand, and of alternative scenarios featuring strategic virtual situations or sensitivity tests of some variables that may be used as leverage in urban transportation planning, such as prices, forbiddances, and network improvements. Among the works brought to a successful conclusion during the research program Eval-PDU, this article presents essentially the impact evaluation as regards atmospheric pollution and GHG emissions, from the point of view of the model chain and the results obtained.