The paper presents some problems related to the design and operation of speed reduction measures on traffic roads in a network with poor hierarchization of roads. The first part points out that speed is a significant road safety factor on traffic roads running through small towns and villages. Then some design recommendations on the use of speed reduction measures and the impacts and effects of these measures are described. In the next part three possible approaches to design, based on the design speed, posted and actual V85 speeds are discussed. The design speed seems rather a doubtful basis for design of speed reduction measures installed in the traffic operation stage. The last part presents some results of research on the effects of some roundabout geometrical parameters on speed. The analysis of the results showed strong effects of entry and exit curve radii and entry lane offset on speed of vehicles. The conclusions highlight the main findings concerning the efficiency of the speed reduction measures on traffic roads and problems of their use and also the necessity of further studies of design approach to measures that also need efficient speed reduction in advance of their location.
Samenvatting