I noticed this was an issue from a few threads back in the FSX and earlier versions of P3D days, but I don't see it being talked about much anymore.  Does anyone still have an issue with road traffic causing stutters no matter what setting?  It doesn't effect my FPS too much at the low settings but it is the only thing that causes stutters.  Otherwise, I'm very smooth.  I run a 4k montor at 24hz and lock it at 25 FPS to help with sharper textures at less demanding airports and run unlimited FPS at the bigger airports so I can maintain 24 FPS.  I never have an issue maintaining smoothness at 24 FPS because I'll always drop down my settings if I have to.  I have a 6600k a 4.4ghz and a GTX 1060 video card.  Is there any way around this stuttering issue?  I don't' want too high but it would be nice being able to run road traffic at 10% or so just so I can have some traffic.

FSX/P3d road traffic suffers from the same problem as AI air traffic. They are both expressed as a percentage of a maximum value. Unfortunately, that maximum value is quite variable and is specifically related to human population density, which is provided to the sim as a default file, PopulationDensity.bgl. And as an aside, where according to Microsoft is the densest population? Around London. And people wonder why performance takes a big hit there. Lot's of building autogen, big airports and lot of AI traffic. And the road traffic doesn't help.

My suggestion to reduce the road traffic percentage even lower than 10%.

12 minutes ago, jabloomf1230 said:

FSX/P3d road traffic suffers from the same problem as AI air traffic. They are both expressed as a percentage of a maximum value. Unfortunately, that maximum value is quite variable and is specifically related to human population density, which is provided to the sim as a default file, PopulationDensity.bgl. And as an aside, where according to Microsoft is the densest population? Around London. And people wonder why performance takes a big hit there. Lot's of building autogen, big airports and lot of AI traffic. And the road traffic doesn't help.

My suggestion to reduce the road traffic percentage even lower than 10%.

For me any % > 0 causes the stutter.  0% is smooth while anything higher causes stutters.  

Where geographically? Everywhere  or just certain places? The Living World SDK which controls road traffic is neither very well developed  nor properly documented. So there is not much that the user can control. Did you edit the Living World configuration XML file at some point? Sometimes people do this to modify vehicle speeds and types.

I tested it further this morning and you are correct it seemed to be happening only in certain places with higher population density.  When I switched the FPS to unlimited it helped a ton with stutters.  For now that's the only change I have to make to get it mostly smooth again but at the expense of blurries.  I can still lock the FPS at smaller airports with road traffic and everything seems fine.  Miami and SFO were the two areas I had issues with yesterday but it appears my system can handle it if I go unlimited FPS and very low traffic settings.  I haven't tested the densest areas such as London or NYC but I imagine I won't be able to have any traffic there.  It's just a tradeoff I have to make I suppose.

Hmm. Well at least you figured out a temporary  workaround.

12 minutes ago, jabloomf1230 said:

Hmm. Well at least you figured out a temporary  workaround.

Yeah it's weird.  I didn't check the FPS too closely before and I thought it was steady at my refresh rate but there were dips every few seconds which would cause the stutter when the FPS fell too far below the refresh rate.