Stress test my layout

[McGherkin]

I think that in the 5th and 7th pic, the barriers for the filter lane should be removed altogether. Much better for someone to completely overshoot the junction and have to go round again than to smash into the barrier at the end and go flying.

The lane which turns into the pits could be filled with yellow lines if necessary. Used on a few roundabouts round here where you have to slow from 70mph. Pretty hard to ignore imo. You've used red ones in the layout but some are in fairly pointless places (high end of the main straight?)