PTV Vissim: A Roundabout with Tram Priority
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- Опубликовано: 2 ноя 2011
- 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. 
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Works perfectly well at the Haymarket roundabout in Melbourne Australia with 3 intersecting tram lines. All the cars have to do is obay the traffic lights.If they dont its their look out.
I can forsee that with this on any major road, peak hour will be a pain to get through this Roundabout. I live in Australia, and we have roundabouts just about every 3rd major intersection. But this style of Roundabout is just... strange.
I wondered about that and thought so. Where I live, there are a WHOLE bunch of roundabouts (both on state highways and municipal roads - multilane and single-lane) and there is a very old one in Portland that has light-rail tracks going through it.
What is the traffic intensity?
I'm not a traffic engineer or anything, but this shows me quite clearly that the tram blocking off the road like that causes horrific congestion (even with those perfect simulation drivers). Either build a bridge or tunnel over or under that roundabout for the tram to pass through without blocking traffic.
If that's a thing you can do.
thats a hell of a lot more expensive, and seeing as it is in city centre, there might not even be enough room for ramps
- really good visualisation
- really bad solution
Hello. What the program did you use?
PTV Vissim is the program
@@ChiehWang thank you
Country town and rural Australians are hopeless with roundabouts - they wait for the world to go by before they enter the roundabout! So, they should take the tram instead!
I'm designing a tramway for a rural centre that floods, so much of the tram is suspended above the CBD streets, but has to negotiate a few roundabouts - that will need to be changed. They're too small anyway. Of course, Aussies think we can just drive around or take the one-a-day bus service [to my town].
We used to have basic integrated rail-based transport, in the seventies, but now about half [from small children to older folk] can't or don't drive, and the huge number of tourists and visitors can't get around the region. Drivers don't consider this.
I have medical illness and disabilities, and need toilets, food medication etc, on journeys that can be up to 3 hours across the region - if we had rail, otherwise much longer by meandering bus routes. We need to extend 'heavy' rail into the CBD etc. by lighter rail services from the station.
My tram and car roundabouts, are nothing like this - except for how the lights and system controls the traffic flow. Apart from tram stops, cars and trams will share part of the road - needing a curved tram track - but not as tight as turning a corner - which trams cannot really do - so it does fit in with a larger 'kidney shaped' roundabout.
Sydney had the largest tramways in the southern hemisphere - perhaps fourth in the world. Car drivers blamed the trams for traffic congestion, as some of Sydney's city streets were not as wide as Melbourne's. But with traffic lights, this may not have been a problem.
Melbourne has the weirdest way for cars to turn right at a large intersection with trams. One has to go in the left lane to turn right, after the lights change and the tram had gone through. Strange for people not used to it, but we should all receive instructions for driving where rules are different.
Give people lights and signs in advance - to get in the appropriate lane. What they need to know on a roundabout is only give way to traffic when it is on the roundabout - don't stop for a ghost car! Probably yellow lights with 'give way to traffic on roundabout' might work. People should know that 'give way' does not mean 'stop'.
Video is very good ? Can you make videos: teach me methord draw car and train. Can you give for me this video ? Thank you verry much!
Let alone the rail, roundabouts have been a great problem for many American drivers....
Germans are intelligent drivers and can process this information and this would work. Pray that this is never built in the US and that no American driver is put into this situation in Germany because many people would die. Americans can't handle using judgement while driving and this would definitely cause a huge accident.
car and rail traffic should NEVER cross each other's paths. Plenty of people sitting in cars getting hit by trains to testify to that reality....if they weren't dead.
Wrong.
This is a light rail train
Don't be silly! Your comment is like something a "teenager who nobody understands" (you know the type, they wear black, smoke clove cigarettes, and think they know everything) would make.
Worst idea ever. Maybe it would work in Germany (they have roundabouts?) but in the Anglosphere, forget it. We have enough issues with train crossings =/