A fixed-point model and algorithms for simulating urban freight distribution in a multimodal context with crossed congestion

Urban road networks, generally, are shared at least by three different kinds of vehicles: private cars, buses and freight vehicles. This aspect implies that these vehicle categories influence reciprocally their travel times (the crossed congestion phenomenon). Hence, in order to simulate the performance of urban road networks, it is worth developing a multimodal assignment model that take into account the effects of reciprocal influences among vehicles on user travel choices (at least on mode and path choices). In this paper, authors extend the model proposed in a previous paper (D’Acierno et al. [1]) to the case of the urban freight distribution simulation, considering the crossed congestion among all considered transportation systems. Moreover, the proposed model is tested on a real dimension network adopting three algorithmic approaches (external, internal and hyper-network) for its solution and comparing their performances in terms of calculation times and result reliability. Finally, effects of the crossed congestion on the freight path choices and influences of the freight vehicle presence on the (road and transit) user choices are discussed.