Work sites represent critical areas on motorways. The required expansion (incorporation of lanes) and the maintenance (restoration or complete renewal) of motorways inevitably leads to an increased installation of long-term and short-term work sites. Previous studies on the use of longer trucks assume that no fundamental risks of new type arise from an increase in the permissible length of vehicles or vehicle combinations. It is however not excluded that the vehicle lengths entail an increase in the number of critical situations, e. g. in transition areas of work sites. Findings which confirm this assumption are not yet available, though. Therefore, the use of longer trucks at long-term and short-term work sites should be analyzed with the aim to obtain research-based findings about the impact on traffic safety and traffic flow at work sites on motorways. Regarding this fact, it is particularly to assess if differences between longer trucks and conventional trucks can be expected. For this purpose, empirical studies on longer trucks at work sites – based on a research and review of international literature on previous findings regarding the effects of longer trucks and heavy traffic on traffic flow and traffic safety at work sites on motorways – were carried out as part of the field test with vehicles and vehicle combinations. A total of 34 long-term work sites with 40 different traffic diversions and 18 short-term work sites with partial lane closures of at least one driving lane were passed through by 16 accompanied longer truck drives of eight different truck companies. All drives were analyzed regarding possible effects of longer trucks on traffic at work sites. The results of the empirical investigations show that no measurable impact from longer trucks on traffic safety and traffic flow at work sites on motorways can be expected. In both long-term and short-term work sites the longer trucks could drive through all traffic routings without any problems or negatively affecting the traffic flow or traffic safety. On the part of other road users, no driving behaviour which was adapted to the longer trucks could be observed. Thus, no increased demands on the safety of long-term and short-term work sites need to be placed due to the use of longer trucks. In this regard the same general requirements apply to longer trucks that generally arise from heavy traffic. (Author/publisher)
Abstract