Picture says it all...
The grass bit/portion contains the pebbley/tarmac bit as you can see in the square (the upside down V shape that is obvious what is textured grass and what is tarmac), and apparently when you put even a quarter's tire width on the bit between the grass and green astro the dirt pickup is so immense it blows you up immediately.
For the avid simracer like me who goes for detail we usually will take the best line (i.e all of the track), and basically predict-position our car for each corner entry, so it ticks me off slightly when I know I'm still on the track (not the grass) but because of the way the plot of land is positioned (and the fact that the tapering off bit is not actually textured grass) I still slide off.
What I'm suggesting is that either fully grassi-fy the half pebbley bit to the very edge of the astro so when we race we recognise the edges of the track better, or increase the detail in such a way that from the edge of the green astro, to the start of the grass - that small grey bit is still actually tarmac.
-ps I'm not ranting, it's just a small suggestion to make the flow better...
Don't ask me or tell me "no!1!! it doesn't affect your racing!" well if you grow heavily accustomed to simracing and have a 6th sense of the track after a long time you'll realise tiny things like this do matter.
Not sure about other kerbs/astro if they have this because I never run that wide elsewhere..
Cheers