Don't trust the bollards in Gran Turismo Sport Gran Turismo Sport Guide, Tips
Last update: 11 July 2018
Double bollards on the route are much more useful indicators of braking before the turn, but do not rely on them 100 percent. Some curves can be overcome by braking a little further, so then you risk getting hit from the back. In a few places there are no double bollards at all, although braking is still necessary there.
However more often, the bollards will be simply mowed during the fight on the track. Some drivers usually land in the sand after, after missing the moment to use the brake. The recipe for this (and the only appropriate method) is to use the track's environment as determinants of the braking locations. Remember particular trees, the beginnings of the colorful curbs, track building objects, and you'll always be able to slow down to the right speed.
Also watch out for the bollards laying on the road. When you drive by them, you can be out of the track, or your car can be tossed, and then you will waste some time. Evade them like holes on roads.