The project focused on the examination of the maneuverability of at grade intersections with heavy goods vehicles. Therefore the aim of the research project was to analyze the deficits in geometric design of at grade junction in urban and nearby urban areas concerning the maneuverability with heavy goods vehicles. In addition to this, the dimensions of the German design vehicles (FGSV, 2001) should be proved. Based on comprehensive on-line questioning of about 250 federal and local road authorities it could be shown, that only a small number of road authorities is involved in problems concerning the maneuverability of at grade intersections with heavy trucks. Most often small roundabouts caused problems. In some cases the wrong choice of the design vehicle is responsible for the damage at the road infrastructure. However, the dimensions of the design vehicles for the heavy goods vehicles did not change for the past 15 years. However, more than before truck-trailer combinations with central axis were covered during the empirical studies. If the German design vehicles will be updated in the future, it is recommended, to add this special type of truck-trailer combination in the catalogue. By comparing theoretical (by software) and practical (by road trials using differential global positioning system) turning templates it could be shown, that software and trial swept path differ only a few centimeter. Curve simulations by software show therefore with right use suitable means to proof the practicability at grade intersections. The systematic comparison of different heavy goods vehicles showed strong differences concerning the space consumption for example by driving into a small roundabout or an intersection. These differences are based on the different physical characteristics of the heavy goods vehicles with different length, different wheelbase and different overhang (front and rear). The different heavy goods vehicles used different trajectories by driving through the different road facilities. The practical road trials also showed different trajectories for various driving speeds and various driving maneuvers. For some types of heavy goods vehicles it could be shown (articulated vehicle with longer semi-trailer, articulated vehicle with trailer and lifted axle), that only a small corridor is available by using the road facility. Minor deviations from this corridor could cause damages at the infrastructure. For unusual or unfrequent heavy goods vehicles it should be proved, if adequate design can avoid problems without making worse traffic safety. (Author/publisher)
Samenvatting