This article concerns the regulation of an urban transportation system using a case based reasoning. This reasoning allows us to associate a profile scenario compared to the disturbances that appear on an urban transportation system. The Transport is essential for measuring the life quality of citizens; local officials have always given special attention. The proposed work contributes to advancing the issue of traffic regulation in an urban transportation system. The latter proposes a new indexing technique called cell technique compared to the classical indexing usually used in case based reasoning approaches. The result of the calculation of similarity between the disturbances is refined through a cell indexing process. This refinement is done by a Boolean Modelling Language (BML) adopted by the cell inference engine (CIE).