Several questions of Traffic Simulation

[Mpcconsultora]

Hello, I have the following questions about the functioning of Traffic Simulation:

1. After running the simulation and reproducing it, when I see it closer I have noticed some weird things, for example cars crashing (see image below) and sometimes cars bumping in the junctions between roads interseccions and the roads itself. I want to solve this, because it would not give a good impresion on our clients.
2. When I configure a Stream, in these case deleting it, after running the simulation, it seems that it does't respect the configuration that I made. How can I fix this inconvenience? See the following images.
3. Sometimes, especially in roundabouts, erratic trayectories can be seen when I execute the simulation. Ocasionally, this entails convergence crashes as seen in the image below. How can this be solved?
4. How much time does the simulation are available in the results tab of the traffic simulation? I'm asking this because I need to review some simulations made weeks before and they don't appear (see image below)
5. When configuring a interseccions with lights, after configuring the turns, groups, phases and timing, there is a tab called Plans where offset can be set. My question is, if this value can be independent from the others? Because not always all the intersections are separated the same distance, so the offset should be different if green wave is desired.

The version of the infraworks that I'm using is: 19.2.12.0

The version of Traffic Simulation is: 6.00.006

The OS: Windows 10 Pro, 64 bits, x64 processor.

I hope you can help me.

[roskirko]

I can just answer in general; the simulation operates more realistically (better driving behavior) in the Traffic Analyst Panel (TAP) (shown under question 2).

You may want to watch a Traffic Simulation demo: https://www.youtube.com/watch?v=yJQpV5WDJ6c

Also this one related to a Mobility Simuation : https://www.youtube.com/watch?v=3hxMO0M6MHw

I have also attached the Traffic Analyst Panel and Mobilty Simulation references. Also attached is the sqlite data for the Traffic Simulation demo.

Perhaps someone at Autodesk can get you in touch with Mr. Gordon Duncan who is the lecturer in the videos and who developed the module, as far as I know.

[spywo]

Have you tried adjusting the signals to avoid the crash? 

 

Once you update the configuration, you have to re-run the simulation. The animation results will be downloaded to your local machine and they are also maintained on Cloud for 30 days. If you switch to another machine after 30 days, the results will not be available for that machine.

[Edmundo.Herrera]

Here is the explanation of what I think is happening without having your model (exact demands). The first response relates to questions 1-3:

1) Default roundabouts created in InfraWorks translate to a specific series of lanes and links in Traffic/Mobility Simulation. For your specific configuration, having two branches with one lane and the other two branches with two lanes in the roundabout, the inner lane along the roundabout shares the same links and nodes as the outer lane along the roundabout:

Since the default configuration creates the roundabouts with the inner and outer lanes of the roundabout with a common node, then even if you delete the links, the movement is still going to be performed during simulation.

To prove my point, here is the corrected behavior on just a quadrant with a simplified model:

First of all, you can see that there is only one common node to all movements. This is critical as then links can be attached to lanes and movements will be honored as expected.

If I then, based on the correct node/link configuration I choose to delete the link, outward movement on the intersection is now only limited to one lane as you request:

Common nodes are critical to control movements on intersections. If not, even if links are deleted, traffic will still be recognized as if links existed.

Once this configuration is cleaned (you will have many more tools and controls using Mobility Simulation rather than Traffic Simulation),  users have full control on movements, especially on intersections. This should also resolve the overlapping vehicles during simulation. Please also check the Minimum Gap distance under Behavior as this controls the minimum distance between vehicles during simulation.

2) If simulations were saved for every traffic study area in proposals, they should be available. If they were not, the list will not be available upon loading the simulation command and a new set of simulations should be ran for every different condition.

3) Yes, absolutely. If you edit the intersection by double clicking on it, Plan settings can be defined per intersection independent from one another.

Thank you,

Edmundo Herrera, P.E.

Autodesk, Inc.

[Mpcconsultora]

Hello Oliver.

Yes I adjusted the signals but when I run the simulation the crashes and interferences still occur.

I have not changed of machine. I did singed out during the holidays and when I signed in again in the same machine I could not re-run the simulation. What should I do.

[Mpcconsultora]

Thank you roskirko.

The problem is that in the Traffic Analyst Panel you can't see any results.

I have seen the first demo that you sent me and it was very helpful. I'll try to see the second one.

As you said, it would be great that someone in Autodesk could contact me with Gordon Duncan.

Thank you again.

[spywo]

Hi Roberto,

Login and logout doesn't remove the animation results. Normally speaking, if you don't see the results, there are 2 scenarios:

1. The TSA (Traffic Study Area) boundary has been modified. You have to run the simulation again since the road network changes.
2. Actually, the results are saved at the folder named AnimationCache in user's temp folder. e.g. C:\Users\<USER>\AppData\Local\Temp\AnimationCache .  If your results were generated 30 days ago and your Windows Operation System also enables the 'Remote Desktop Session Host', then those results might not be displayed in InfraWorks. You can rum 'echo %temp%' in Windows cmd console. If the RDSH is enabled, you will see something like: C:\Users\<USER>\AppData\Local\Temp\<NUMBER>. What you can do is to figure out where the AnimationCache  folder is located and copy it to the current temp folder.

[Mpcconsultora]

Hi Edmundo, I will be replying what I understood and what I have been experiencing on each of your comments:

1) If I undestood well what I should do is what the images below show:

So, if I "clean" the stream of the one lane brach entry and configure it so that all one lane branches enter only in the outer lane of the roundabout, would the simulation run would work well?

I am starting to use the Traffic Simulation, so I don't know what is the difference with Mobility Simulation. I will try to use the mobility. The specific question is, when should I use the Traffic or the Mobility Simulation?

2) The simulations where saved and I am sure of it. I did several simulation on several proposals, but now I can't view neither re-run them. What should I do?

3) I think you didn't undestand my question. Specifically what I was asking was about creating a green wave in a model of 10 light intersections, but all the intersections are separated a different distance, and when I try to define a offset in the plan tab on one intersection and try to change it in other intersection, it changes the value in the first one. See the images below that, first, in intersection 3 I put 5 seconds offset and the on int. 4 I put 7, then return to 3 and it automatically appear 7.

Another extra question: how could I renumber (or reoder) the intersections? Because in this model all of them are ordered (from the beggining to the end) except the last intersection.

Thank you.

[roskirko]

That is true; one cannot see the results volumes, however, the preview shows traffic moving. What I experienced previously once or twice is that the preview shows well behaved traffic as opposed to what sometimes happens in the Traffic Study area. 

I have attached a screencast..

As well; here is the link: https://autode.sk/2B02p74

[Edmundo.Herrera]

Roberto:

Here are my responses:

1) In order to rename any intersection, right click on it and select Edit > Rename.

2) I have tested over and over the Plans issue scenario with a wide variety of offset values. It always works. I completely understand where you are coming from but I am not able to replicate it. Even with scrambled intersection names (not making sense from a modeling standpoint of view), the values are honored. Furthermore, once I simulate, not only the numbers are making sense, but the signals are modeled to the exact second. Kindly share your model with me as we absolutely need to get to the bottom of this.

3) There are considerable differences when using Traffic & Mobility simulation

Traffic Simulation

- Private Vehicles only (cars and trucks)

- Simulation on cloud

- Animation in main InfraWorks

- Delay and queue results in InfraWorks

Mobility Simulation

- All vehicles (cars, trucks, buses,trains and taxis)

- Pedestrians and cyclists

- Simulation on desktop

- Mobility simulation is a separate desktop tool

- Mobility simulation is launched from InfraWorks but does not send results back to InfraWorks - simulation is viewed and performed inside Mobility Simulation

- Files can be saved and shared without an InfraWorks model

4) Having said this, please use Mobility Simulation (not need to define a new area - just inherit it directly from Traffic Simulation), try again placing offsets on intersections and without even simulating, verify if the values hold. If not, save the *.aza file and send it to me. I will then be able to open it and check it.

5) Finally, I was referring to correcting the streams and nodes where the inside and outside lanes are independent from each other.

Thank you very much. Looking forward to receiving your aza file.

Edmundo

[Mpcconsultora]

Edmundo:

1) What I was refering was about the numbering (not the name) of the intersections, in order to have a correct secuence in the Traffic Simulation. I send the following images so you can understand what I say in better way.

So, as you can see, the secuence is NOT honored because the last intersection (nº6) es the fifth in the secuence (of a total of 12 intersections). I am asking this because I don't know if the offset (of the light's Plan) of intersection Nº6 is going to reffer to intersection Nº5, and the secuence of intersection Nº7 is going to reffer to intersection Nº6... that wouldn't make sense.

2) Does the Mobility Simulation give delay and queue results? Because in this case, what I'm looking for is the queues and delays that a syncronized lights system (green wave) is going to result from a model, in both, the main road and the secondary ones.

3) In this message I will send you the .aza files (from Mobility Simulation) and I will send you the model of Infraworks after.

Although, in Mobility Simulation I don't have the problem of setting individual offsets in the Plan configuration of each light intersection. My problem would be the numbering of intersections, as I said in point 1.

In the .aza files you should pay more attention in proposals: "Propuesta1", "Propuesta2", "Propuesta3" that are the ones that include more than one intersection.

Thank you.

[Edmundo.Herrera · Accepted solution]

Roberto:

First of all, I am glad that the Offset time is resolved for all intersections (your original request). I got your .aza files and I am able to load the entire network, thank you.

Secondly, the order in which intersections are displayed with the Adjust functionality does not impact the Offset time. It honors the offset based on the "origin" regardless of the order on Intersections.

Take a look at the images. Just with your naming convention, Intersection 3 at 8:04 is exactly where the phasing starts (tweaked groups and phases just to reproduce your scenario):

Now, at the same 8:04 on Intersection 6, cars do not move.

If Intersection 6 has a 10 second offset phase, then, exactly at 8:04:10 is when cars will start moving on Intersection 6 (previous intersection, Intersection 17 had a 5 second offset. It obeys Intersection3, not 17):

Finally, if you are adamant about re sequencing intersections and that makes you feel better (not necessary but certainly more comfortable as you are navigating using the Adjust command), then, start renaming Intersection 6 to a very high number, then 17 to another high number, and so on. Now that the Intersection 6 name is available, rename it and then all intersections will appear in the correct order.

Thank you very much,

Edmundo Herrera, P.E.