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At traffic hubs, it is important to avoid congestion of pedestrian streams to ensure safety and a good level of service. This presents a challenge, since distributing crowds on different routes is much more difficult than opening valves to, for example, regulate fluid flow. Humans may or may not comply with re-directions suggested to them typically with the help of signage, loudspeakers, apps, or by staff. This remains true, even if they perceive and understand the suggestions. Yet, simulation studies so far have neglected the influence of compliance. In view of this, we complement a state-of-the-art model of crowd motion and crowd behavior, so that we can vary the compliance rate. We consider an abstracted scenario that is inspired by a metro station in the city of Munich, where traffic regulators wish to make some passengers abandon the obviously shortest route so that the flow evens out. We investigate the effect of compliance for two very simple guiding strategies. In the first strategy, we alternate routes. In the second strategy, we recommend the path with the lowest crowd density. We observe that, in both cases, it suffices to reroute a small fraction of the crowd to reduce travel times. But we also find that taking densities into account is much more efficient when facing low compliance rates.

Stress concentration factors (SCF) related to specific geometries, loadings and stress quantities can be calculated efficiently using approximate equations. Those relations are typically based on metamodeling via the results of linear elastic analyses. Existing equations for the, technically speaking, very important circular shafts with shoulder fillets or U-shaped notches under bending, torsion or tension/compression can be appropriated, for example, from the DIN 743-2 : 2012-12. Using these relations requires compliance with underlying constraints and assumptions. For example, equations from that code do not provide SCFs larger than 6 and refer only to the maximum principle stress. Furthermore, DIN 743-2 : 2012-12 does not provide SCFs for combined loading, i. e. simultaneous bending, torsion and tensile/compressive loading. This paper presents new and improved equations based on sampling computational finite element simulations and subsequent regression analyses. Multiple improvements could be achieved: The six equations for circular shafts with shoulder fillets or U-shaped grooves derived from DIN 743-2 : 2012-12 were simplified down to two equations. Despite this simplification, the new equations have been generalized for combined loading and include SCFs larger than 6 as well. Choosing between various equations for each type of loading is no longer necessary. Only one equation for each of the two basic geometries is needed. Moreover, two further equations which refer to von Mises equivalent stress have been added. Although the new equations are easier to handle and allow for an estimation of stress concentration factors larger than 6, the accuracy of the new equations is higher than the accuracy of DIN 743-2 : 2012–12 when compared to SCFs derived from finite element simulation as reference values.

New generation mobile communication protocols, such as the 5G standards, allow direct communication between devices. This allows to disseminate information directly in a moving crowd. In a safety concept, this information could be used to redirect pedestrians away from danger. We couple state-of-the-art computer models of pedestrian motion and mobile device-to-device communication to build a model of this complex socio-technical system. The model captures the interplay between information dissemination and human behavior. We further harness methods of uncertainty quantification to pinpoint the parameters that most influence the systems functionality for a scenario where pedestrians are redirected. We bundle successful analysis methods to suggest a procedure for future studies. We find that, in our scenario, there are rare cases of information dissemination delayed by shadowing and additional network load from apps, where agents cannot be redirected in time. Our simulation tools and methodology can help to detect such problems and serve as a basis to investigate more complex scenarios and rerouting strategies.