Over the past decade, the Macroscopic Fundamental Diagram (MFD) has appeared to be a powerful tool to describe traffic states at the network level with few implementation and computational efforts. Many studies (e.g. Knoop & Hoogendoorn, 2014, Yildirimoglu & Geroliminis, 2014, Yildirimoglu et al., 2015, Haddad, 2015) have notably used MFD-based traffic simulators for several applications, like traffic state estimation, perimeter control or assessing routing strategies at a large scale. Their modeling approaches take advantage of the multi-reservoir representation of a city, where the dynamics of each urban subregion is described by the single reservoir model of Daganzo (2007). This framework, also referred as the accumulation-based model, assumes that the reservoir outflow is for the simplest model proportional to the total circulating flow inside the zone or that partial outflows are proportional to fractions of the circulating flow for more advanced models. However, while being acceptable in slow-varying conditions, this hypothesis may be too restrictive when the demand evolves too fast as shown by Mariotte et al. (2017). An idea, initially proposed in Arnott (2013), has been exploited in Daganzo & Lehe (2015) and then Lamotte & Geroliminis (2016) to design a 'trip-based' formulation of the MFD model. This approach considers that all users travel at the same speed at a given time, and exit the zone once they have completed their individually assigned trip length. As shown in a thorough comparison with the accumulation-based model by Mariotte et al. (2017), the trip-based approach gives more accurate results during transient phases, and proves to be more flexible to integrate various trip lengths inside the same reservoir.