PCA Southeast Michigan Region

From the Blog

P4-2018-09 – Consider the Apex

ByTom Fielitz

The apex of a turn is most possibly the single critical yet often least focused of the many aspects of driving.  By that I mean that it plays a crucial role in almost every driving situation yet it is often ignored or minimized as a skilled aspect of driving.  By definition it is simply the geometric center of a turn.  To most of us the apex only applies to driving on a closed circuit or race track.  In actual fact every driver faces making driving decisions on a constant basis every time we drive even on public roads.  Our apex decisions affect our own driving as well as the driving of those of whom we share the road.  A poorly chosen apex might encroach on the space given to other drivers or in worst case might even impact the safety of others.  Without choice every driver has to constantly be aware of and make driving decisions about the apex choices they make.   Yet upon reflection we can agree that this is one aspect of driving that receives much less emphasis than it deserves.  The oddity about apex instruction is that it is a very elusive construct.  We know what an apex is and how important it is but at the same time it is difficult to describe a perfect apex as much as it is to consistently drive to a perfect apex.

If I am in the instructor’s seat with you at a driver’s school you will receive constant instruction about “hitting” the apex.   We can mark where the apex is on a track corner with a bright orange safety cone but even that is only an approximation, or reference point, and not an absolute marker that applies to all drivers and all cars.  In classroom instruction sessions the apex can be drawn up on a white board and can even be distinguished between early, perfect, and late apex points and the significance of choosing each one.  Once the student is on the track it becomes quickly evident that white board apexes and real apexes are very relevant but also very difficult to recognize much less achieve.  Driving to an apex point becomes a real challenge as the student believes perfection has a tolerance point of up to a foot where the instructor expects less than an inch.  Just to confuse things there are situations where the visual apex point and the actual apex point are not the same.   In certain corners and certain road situations the actual apex point may not be at the edge of the track.  The camber of the track or even the track surface might dictate a different apex point than what may be marked with a cone.  That often elicits the instructor comment that you will know the correct apex when you feel it.  That is not necessarily a comforting instructor feedback when a driver is hoping to impress their instructor with their apex prowess.  Yet this is exactly how we expect driving an apex to be learned.  It is an imprecise skill that is almost all feeling and not nearly as precise as the rest of our driving skills.

The big deal about the apex is that it has a disproportionate impact on negotiating the corner as a whole. Get the apex wrong and all hope of negotiating a corner smoothly or effectively is beyond possibility.  Missing an apex can mean just not reaching peak speeds but at the worst not negotiating the corner at all and can result even leaving the track surface.  Do this on a race track and perhaps it only gets your car and tires dirty.  Leaving the road surface on a public road can have far more serious implications.  I don’t even want to broach the impacts to safety barriers on track or road.  Trees are not safety barriers and they are serious threats to bodily injury.

By this time I hope you will reconsider the importance of an apex.  We might spend a majority of our concentration on achieving the maximum brake point.  Or we might focus on that specific point where we can apply the throttle on corner exit.  We might even focus on achieving an arc through a corner that maximizes using the entire width of the track or road surface.  But if we have not focused on putting the car precisely on the optimum apex of a corner we cannot possibly achieve any of those other markers.  On the track or on the road the apex of any corner is worthy of our complete concentration and a worthy goal to celebrate in any driving situation.