Each turn on a track has its own ideal trajectory that is easily identified when the curve connects two straight sections but requires a more observant study when one turn follows another. In this case, the second turn might be in the opposite direction, making an S, or in the same direction as the first one. 

In all three cases, the reference for those behind the wheel is what’s known as the ‘apex’ of a corner – also known as the clipping point, which is the mid-point of the turn, when the driver comes closest to the inside kerb of the turn. In this case, we are not talking about braking or speed, but simply about the best flow and position on the track that the driver should aim for. 

If the turn is a single one, let’s take for example Druids corner on Brands Hatch, the one that follows the descent after the pits, the goal is to squeeze on the power as soon as you’re out of the corner to power you down the hill. To achieve this, the apex isn’t exactly halfway round the corner, but significantly earlier. (Slide 1)

If the curve is an S, such as the medium speed right-left-right at Les Combes on Spa-Francorchamps, it is necessary to sacrifice a little performance on the first in order to find the ideal apex point of the second curve, again, giving you the fastest exit. There is no fixed rule here, as each track has its own ideal trajectory that is normally recognizable by the traces left on the track by the tires. (Slide 2)

An interesting case, because it can have an important impact on lap times is the Pouhon double apex left-hander, one of the finest corners at Spa-Francorchamps. Here, the ideal trajectory is finding the two apexes of the two separate curves as tangents of a trajectory that has a third reference point on the outer part of the connecting section. (Slide 3)