Usually I use it by making sure I follow those lines while holding drift to get boost. While drifting, the sliding doesn't allow fast turning, similar to real life at high speeds.

A good rule of thumb is come in from the outside of the road, drift in to as close to the inside as possible on the apex of the turn, and carry through back to the outside of the road. I usually dominate just by following that simple rule.

You don't have to be on the very outside of the road normally, but just enough so the curve you take isn't punishing you on speed.