Bu-aya! (Crocodile)

On the way home from Davao we saw something really interesting! As we came through Bukidnon, we saw trucks, jeepneys and some motorcycles lined up by the side of the road. Hmmm, could this be a traffic check? Yep, sure enough, there were the highway patrol guys standing there stopping vehicles, 100 yards beyond the last parked truck! 100 yards beyond the check point, another long line of parked vehicles began on the opposite side of the road, all waiting for 5:00 pm to come when the cops go off duty. As we came into Cagayan de Oro, there was another line of parked vehicles, this time even longer, (at least 50 trucks on each side) Same thing, another traffic check point, with another long line on the opposite side!

My question is, if these people know there is something wrong with their registration or whatever, and have therefore stopped rather than pass through the check point, why don't the police simple go up the line, examining them all one by one? But the don't. They just stand in one spot and catch who they can.