  In this paper we deal with pedestrian modeling, aiming at simulating crowd
behavior in normal and emergency scenarios, including highly congested mass
events. We are specifically concerned with a new agent-based,
continuous-in-space, discrete-in-time, nondifferential model, where pedestrians
have finite size and are compressible to a certain extent. The model also takes
into account the pushing behavior appearing at extreme high densities. The main
novelty is that pedestrians are not assumed to generate any kind of "field" in
the space around which determines the behavior of the crowd. Instead, the
behavior of each pedestrian solely relies on its knowledge of the environment
and the evaluation of interpersonal distances between it and the others. The
model is able to reproduce the concave/concave fundamental diagram with a
"double hump" (i.e. with a second peak) which shows up when body forces come
into play. We present several numerical tests (some of them being inspired by
the recent ISO 20414 standard), which show how the model can reproduce
classical self-organizing patterns.
