Thanks for the very comprehensive and informative post. I was aware of most of those means of keeping cars on the track, but they don’t seem to be doing a very good job. If you give the drivers an extra inch, they’ll take an inch. Kerbing and runoff don’t solve the problem of drivers exceeding the track limit, they just move it a few feet.
The paint at Paul Ricard sounds like the kind of thing I was looking for; something that would take the car off its desired line and force the driver to slow and rejoin the race. I’ll have to watch the next race from there and see if it works. I noticed in the race today at Monza that cars were routinely putting all four wheels off the track at the second Lesmo, coming out of the Ascari chicane, and at the Parabolica.
I noticed that it took several minutes longer for the stewards to decide the penalty against Hamilton than they did for Giovanzzi, for the exact same infraction. During the red flag the commentators discussed whether Hamilton should have seen the lights indicating that the pit entrance was closed. They didn’t mention that every other team (save Giovanazzi’s) kept their drivers on track.