I believe, as you approach a checkpoint, it purposely shows the direction of next one. Reasoning for this is so that people know where the next one is so that they can prepare for it in advance.
If this feature wasn't there, following checkpoints would likely be much harder, especially when going at speed and/or not knowing the route by heart.
Could perhaps be tweaked a bit - have the distance from the current target needed to switch be dependant on player speed? so... if going slowly it'll switch target much later than if you're going fast towards it? Not sure exactly how it's currently implemented - might just be one massive hitbox, in which case you'd have to dynamically scale them every tick... You'd only need to scale the next checkpoint though, so it might not be very computationally costly and if you think from behind is annoying, could shift the hitbox over a bit so it's weighted towards its front?