area around Jonkoping, something's odd?

[Josh0]

However there is not a direct correlation between tc and framerate, sometimes it might just be 1.5 mill and there is terrible lag whereas in Spain it is sometimes above 3 mill without significant lag. Perhaps someone can elaborate a little on why that is (I'm sure Josh knows something more ).

As you can see from the above, jittering (fluctuating fps) can happen even with tc as low as 1.7 mio. Or sometimes I can drive quite smoothly through an area with 2 mio average tc.

The short answer, although not very satisfying, is that there is more to GPU/game performance than simply triangle count. I am out of my depth at this point. I don't think anyone would disagree that too many triangles will lead to poor performance. But for the sake of discussion, if we ignore things like hard drive access times, memory bandwidth bottlenecks, background processes, etc then I suspect the next largest contributors to graphics performance would be the complexity/size/number of textures, and lighting/shadows/reflections. Weather and environment can also cost some performance.

A few topics come to mind which contain some relevant information to the discussion of game performance:
Stockholm and Sodertalje Not Optimized
Framedrop and lags since 1.9x

... note being inside the truck adds a few hundred thousand to tc ...

More completely, A.I. traffic and the player's truck/trailer will increase the triangle count in any view; I'm not sure these things are factored into the ProMods map developers' triangle count targets, as traffic is quite variable/dynamic.

High triangle counts (even above target) are found in certain places in the ProMods map, and I agree that those areas could be better optimized, but there are usually higher priority problems for the developers to work on.