The aim of this research is to investigate whether the database “Road signs” could be used to homogenise speed regimes. It also examines what the effects of homogenised speed zones could be on the number of road signs. Driving speed is an important factor in road safety. Speed not only affects the severity of a crash, but is also related to the risk of being involved in a crash. The speed is not only a quality criterion within a transport system but should also take into account the need for structural safety margins. A human as the vulnerable road user is the weakest element in the road traffic system. This vulnerability explains the injury in an accident. The vulnerability is in relationship with the purely biomechanical properties of the human being, the speed-related released kinetic energy in a collision and the characteristics of the vehicle. The number of accidents depends heavily of the varying conditions in traffic and environment. Flanders, with its fragmented space and his historically not very well planned underlying road network, is characterised by strong changes in road structure and environment. Most research reports conclude that speed differences at road section level (larger speed variance) is related to higher crash rate. However, - taking into account these varying characteristics - the number of changes of the speed limit on a road has to be kept as limited as possible. Changes in the speed limit and differences of speed in the traffic flow and speed differences between different vehicles increase the risk of accidents. Larger differences in speed between vehicles are related to a higher crash rate. Without exception, a vehicle that moved (much) faster than other traffic around it, could have a higher crash rate. There is also – mainly because of the limitations of the capacity of the road user –a need to simplify the traffic tasks. Homogeneity in the traffic flows is needed. If this is translated to the characteristics of the vehicle, the mass and speed of the vehicle along with the ...