Question about water puddles

I did a rain race at Oulton Park. Barely any water was pooling.
Naturally I assumed that perhaps the race duration wasn't long enough so I then created a session with same amount of rain but 60x time scale.
Puddles did form but they seemed too few and never in places where I'd expect them. For example no water was pooling inside the carousel ( on camber/downhill turn therefore the inside curb should be quite saturated ) and no water was pooling in the grid dip just before the last corner.
I then decided to try an extreme rain preset ( thunderstorm ) to see if the volume of water would change and as such the rate at which the track floods. 60x time scale again. I did see an increase in puddles but once again they were too few and not really where they " should " be.
I put should in quotes because I don't exactly know where there is bad tarmac in Oulton but once again I would expect gravity doing its job and pooling water in places where it has nowhere to go i.e. big race track dips or curbs.
My question I suppose is whether I am doing something wrong , or whether it's completely random or if puddles have been nuked almost entirely from livetrack.