Solved

Training

I trained my driver's physical first and it maxed out, so I changed training to all. When the training bar went above 100 it displayed no change, why?

When you pick all it randomly chooses an attribute to increase (well all options do). It may have chosen to improve your physical stats, which you said we're at maximum. It is better to manually choose to work on physical or mental to ensure your training has an effect on an attribute than can actually be improved

+1 to Greg's answer.

Thanks I will take care of it

Which stat define that your driver is at maximum level. I´m at level 12 and when I train drivers driving skills it doesnt have effect his stats. His all driving skills are at lvl 20..

Attributes are maxed out when they reach 20, the number in parenthesis next to the star rating indicates driver level.

So when is possible to increase Category: driving ability over 20? It always says "no effect".

You can't go past 20. If you see "no effect" then it means the category for a driver is fully trained and cannot progress any further.

I assume this will be your 'Stamina' stat. Change your training so instead of training 'All' or 'Physical' you can change it to either 'Driver' or 'Mental'.