Above all, be considerate to your fellow travellers. I can understand why folks might think it's OK to dump water while running down the road, because they KNOW what is being dumped - just water. HOWEVER, put yourself in the place of another motorist, either 4-wheeler or motorcycle, who DOESN'T know what is being dumped. In that case, wouldn't you be just a little concerned about what is being sprayed all over you and/or your vehicle ?? In this case, I vote emphatically for NOT dumping on the road.
2003 Ford F-350 V-10 Crew Cab 4WD Long Bed
2004 Jayco Designer Medallion 29 RLTS 5th wheel
Bill, Gayle, and Mindi (dachshund)
Retired at last !
Nothing is foolproof to a sufficiently talented fool.