Roundabout network strategy?

I’m creating an animation of a roundabout and have run into issues creating the road network. My initial thought was to create a closed loop set as Primary priority for the roundabout and have the entrance/exit legs as intersections without traffic signals and set as Secondary priority. In practice, I had a very difficult time with vehicles wandering out of the loop and driving off in random directions. I initially thought the numerous intersections were the issue, so I started from scratch with just a loop with a vehicle count of 1 and that vehicle would leave the road and go wandering off.

Eventually, I sort of got things to work by patching together two primary through lanes with multiple secondary entrances/exits, and I joined the two paths with some short secondary segments to create a loop. This mostly works, but there are a few instances where vehicles inside the roundabout yield to vehicles entering the roundabout due to the way I had to set up the various primary/secondary paths. It would be ideal to have just the roundabout as a closed loop with primary priority and everything else with a secondary priority.

I saw the roundabout example in the documentation, but that layout does not follow the designs of most roundabouts I’ve seen in the US: a relatively small circular loop with entrance/exit legs intersecting it at various angles.

Any suggestions on how best to layout a network for this style of roundabout?

Hello Scott,

We already talked about this in the support ticket you opened about 2 weeks ago, I would like to share also here some of the topics we talked about when we were working on this.

This type of roundabout has level of complexity that is still hard to solve using Anima. That said, we think you did a great job designing the road network on that intersection and your simulation is pretty smooth overall. I have the feeling that your final design was a bit different from the one that can be seen in these screenshots, so I invite you to share your final solution here too so other users can see a design pattern that can be used to solve this type of intersection.

About the random animations you mentioned, as we told you in the ticket, we could also replicate them in our own testing environment and that is definitelys something we need to fix. We are not sure yet about what is causing that odd behavior, but we suspect it is related to the geometry background you are using. It seems the slight change in height between the path points is causing those problems. However, it is challenging to know exactly what is causing it because there are many factors involved (speed, steer-wheel radius, collision angle with the terrain). This has been already reported to the devs and it is awaiting further investigation from their side.