Why should a motorcyclist avoid "riding in the wheel tracks" of the vehicle directly in front of them in heavy rain?

1. Those tracks are deeper and collect more water
2. Riding in vehicle wheel tracks during light or moderate rain can be safer because they push water aside, but in heavy or first rain the strip between tracks accumulates oil and water
3. Wheel tracks reduce visibility of other riders
4. Wheel tracks are always smoother than the rest of the lane