Collaborative transportation systems are relatively new concepts in research, but are very popular in practice. In the last years, collaborative transportation seems a good city logistics alternative to classical urban consolidation centers, but it is still in a development stage. This paper proposes a framework to define and evaluate collaborative urban transportation systems. This framework is organized in the following modules: a knowledge management system, a scenario simulator, a transportation management system, an environmental module, a risk factor estimation module and a multi-criteria decision support method. Finally, five realistic scenarios for the urban area of Lyon (France) are simulated and discussed to illustrate the proposed framework possible applications.