  Mobility-on-demand (MoD) systems, especially ride-hailing systems, have seen
tremendous growth in recent years. These systems provide user-centric mobility
services, whose users expect a high level of convenience. Waiting for a
response after an app request and eventually learning after a long period of
time that no vehicle is available is hardly acceptable. This study investigates
the use-case where users should be served within a certain maximum waiting
time. Under certain assumptions, which are reasonable for an attractive MoD
business model, it can be shown that an operator using dynamic state
optimization can communicate a rejection to users after the first iteration,
thereby eliminating unnecessary waiting time before these users would leave the
system. Furthermore, early operator rejections reduce the dimension of
subsequent customer-vehicle assignment problems, thereby saving computational
resources and solving the problems faster. In turn, this allows shorter
re-optimization cycles and once again faster responses, i.e. a better user
experience.
