The problem of having to estimate speed and travel time is also present in traffic modelling. In order to make the most
accurate representation of traffic flows, occupancy of private sections of the network, as well as considering the issue more
broadly - travel behaviour, the average speed for each type and sub-type of link and mode of transport should be properly
estimated. Although the speed of private transport is widely discussed in literature, in the case of public transport fixed travel
times are generally assumed due to scheduling.