How to Change the Value of Social Force Model’s Relaxation Time Parameter with Desired Speed Such that Bottleneck Flow Remains Unchanged

When simulating pedestrian dynamics with the Social Force Model or one of its variants one may commonly be faced with the situation to have calibrated the model such that the model reproduces capacity flow values at bottlenecks which have been observed or which are required by a guideline or regulation, but that then the need arises to change desired speeds. The question is then how the values of the other model parameters need to be adjusted to recover the original flow value. In this contribution it is shown that to achieve this it often suffices to adjust the value of paramter \(\tau \) and how the new value can possibly be calculated.