Modern technologies in the public transportation sector offer a variety of opportunities to advance solutions for every-day use, such as trip planning. Oftentimes, buses and metro lines do not adhere to their schedules, e.g. due to traffic congestion or overcrowding. In such cases, realtime information on the transit system may be used to find faster alternative routes. This paper analyses the quality of a realtime data set that is the first of its kind in Europe, since it covers a whole country, i.e. the Netherlands. The data are published in the General Transit Feed Specification (GTFS)-realtime format as a live-feed. These interoperable feeds, if shared with the public by transit agencies, can be used by developers to write customized applications for public transit users, e.g. through integration with the OpenTripPlanner (OTP) routing platform.