Due to the growing demand for road infrastructure renovations and the upcoming new Technical Regulations for Roadworks (ASR A5.2), which require a greater safety distance between the construction site and the traffic, the installation of lane-drops at highways will be increasingly required before roadwork sections. Hence, the task of this project was to design a Lane Reduction Control System (LRCS) aiming to facilitate the inflow and manage the capacity of the bottleneck in the best way possible. The developed control algorithm mainly consists of two components, the Lane Changing Control (LCC) and the Variable Speed Limit Control (VSLC) for inflow reduction, which can also be implemented independently from each other. This is a closed-loop control system, which, in contrast to conventional thresholding methods, adapts the signaling according to the road-users’ behavior and the predefined threshold values, until the algorithm reaches and maintains its objectives. The effects of the VSLC could be shown in microsimulation, under the precondition that a speed limit as low as 40 km/h can be applied, with the reason being that using higher speed limits cannot keep the in-coming flow within the capacity of the bottleneck. The signalization of the VSLC can be implemented according to the StVO and RSA regulations. In contrast to the VSLC, the LCC could not be investigated through microsimulation techniques, due to the fact that the reaction of the road-users to the respective signals, which is required as an input variable, is not known beforehand. A number of signal layouts were designed and discussed both with experts and road-users. As an outcome, it is suggested that the LRCS should be implemented in a test-field, so as to investigate the clarity, the acceptance and the compliance of the proposed signal layouts by the drivers and therefore the overall effectiveness of the LRCS in reality. (Author/publisher)
Abstract