Tram Priority Roundabout Simulation | PTV Vissim | Product Demo скачать в хорошем качестве

Tram Priority Roundabout Simulation | PTV Vissim | Product Demo

http://vision-traffic.ptvgroup.com/en... - This PTV Vissim traffic simulation shows a roundabout based on a large intersection of a major German city. The model was built in the process of a feasibility study to show how a new tram line could fit in the existing road network. The intersection layout was slightly adapted compared to the existing situation to accommodate for the tram line along with a realistic roundabout operation. Individual traffic: The roundabout itself is designed with a spiral layout in two directions. These lead vehicles directly to the desired exit lane once they entered the roundabout on the correct lane. This method is advantageous over a "normal" dual-lane marking of the circular driveway because no lane changes are necessary inside the roundabout. This results in a plus in safety and increased flow capacity. On each entry/exit of the roundabout, pedestrians may cross and are given priority by the cars. Trams: As long as no tram demands for passing the roundabout, no signals are present for the remaining traffic (in the simulation the signal heads are shown at their stop line position with the corresponding color). Only when a tram is approaching, the signal control is activated to provide a smooth passage through the roundabout without delay. If two trams approach (one from each direction) around the same time, tram signals will be kept at green to accommodate for both tram passages. Microsimulation: Multi-line roundabouts can be quite challenging for modelers of a traffic simulation. VISSIM offers excellent modeling tools to cope with the many different aspects of traffic movements. Just to name a few: (1) conflict areas are used for the pedestrian crossings. Apart from traffic waiting for pedestrians to pass, they also keep the pedestrian crossings clear in case of spillback. (2) VAP signals control the tram crossings using detectors and a tailor-made control logic. (3) Priority rules are used for roundabout entries. They allow for fine tuning gap acceptance and spillback behavior - also in more complex situations as seen in front of the right-hand tram crossing. (4) Routing is designed to take advantage of the spiral roundabout layout and in order to prevent vehicles from unnecessary lane change. Still lane changes are possible in most places and appear at some situations. Sometimes these lane changes lead to a situation which appears to be close to an accident - actually this happens in reality as well as we are looking at a high-demand peak hour where drivers are more impatient and hence accept smaller gaps. The conclusion is that complex multi-modal traffic flows can be evaluated with VISSIM in a single microsimulation model to enable a profound and detailed analysis for present and future scenarios.