As indoor navigation matures, advanced navigation services for users with special needs become possible. We argue for the development of Indoor Traffic Report systems. While a typical user might only be slightly inconvenienced, when an elevator is out of order or parts of a building are being renovated, this may present an insurmountable challenge to wheelchair users. In this paper, we discuss the challenges and possible approaches to building such a system. Common users of an indoor navigation system do not consider checking if an elevator is temporarily out of order or if doors are locked after opening hours expired. In contrast, users of wheelchairs depend on this information. Otherwise, they might be trapped between steps or in front of a locked door. An indoor navigation system aware of the exact details of the wheelchair user's restrictions and the current building status helps the user to avoid these situations, where they are helplessly trapped. As one of the authors is personally affected by these challenges, this paper aims to identify requirements for such navigation systems. How accessible a building is, depends heavily on the exact type of handicap a wheelchair user faces: Shallow steps or inclined slopes might be passable with one wheelchair, but not with another. Next to the question, if an elevator is operational, the type and timing of the elevator door may have significant influence on if an assistant is needed or not. If there are automatic doors, at what height are the controls? Are there transient barriers, such as construction sites or is the elevator out of order? In addition to the user requirement analysis, we propose ideas for data formats for an Indoor Traffic Report System, as well as a data collection system to detect transient barriers using privacy aware crowdsourcing. As an example, consider that other occupants of a building follow their normal daily activities. Their smart devices may detect, that a subgroup usually takes the elevator. If none of those and no one else is taking the elevator, the probability of the elevator being out of order rises, and a wheelchair user might first want to check back via phone or email, if it is operational. Similar methods exist for other barriers. Awareness of requirements for dynamic route planning for wheelchair users promotes the idea of inclusion, while the aging population in industrialized countries warrants more research towards accessibility and barrier free mobility. We suggest requirements for a dynamic route planner for wheelchair users, as well as approaches for crowdsourcing transient barriers. Keywords-Dynamic route planning; requirements, wheelchair