In the framework of this supplementary study, regarding the field trial of longer trucks, investigations have been conducted how technical regulations for vehicles and vehicle combinations with extra length (LKWÜberlStVAusnV) have been implemented by the participating freight forwarders. This study is based on the information which has been provided by the participating freight forwarders as well as on vehicle examinations. It depicts the state of 15th July 2013 with 43 longer trucks of 23 freight forwarders. 31 longer trucks of type 3 represent the biggest share. Alternative possibilities of implementing technical regulations with respect to axle load monitoring systems and camera-display systems for the rear were extensively examined. The axle load monitoring systems do not feature any specifications concerning their accuracy. Sample measurements however show a sufficient accuracy for identifying eventual overloading states. Objects behind the vehicles can be perceived by means of the camera-display systems. However, depending on the camera position they are rather suitable for observing the rearward traffic or as a reverse driving assistance. The turning behaviour of the vehicles according to § 32d of StVZO were examined by simulations and driving tests. These examinations revealed an insufficiency of the test specification leading to different results, especially for longer trucks, depending on its interpretation. The study also revealed a shorter braking distance at 40 tons total weight and a similar pulling effect on two-wheeled vehicles of LGV compared to conventional commercial vehicles. Moreover, differences in the driving dynamics were itemized by means of simulations. This pointed to further need for research. The effectiveness of the rearward labelling of the longer trucks was examined in questionnaires. This inquiry shows a higher effectiveness of pictograms which should be preferred to written labels. The analysis of fleet telematics data demonstrated a carbon-dioxide reduction of a longer trucks of about 15 percent compared to a conventional commercial vehicle if both vehicles are laden with the same kind of goods. (Author/publisher)
Abstract