drive bys trigger strikes on tip ups ?
If you use large enough bait, this is reinforced by number of false trips you get from big shiners or suckers making a run.
Lake Winni - fishing slowed down midday - all of a sudden you could hear a train coming at us as a new pressure heave formed from south to north - as the crack was approaching and passing by us 10 yards away, lines started popping, almost every perch we caught during the minute was over 10".
Upper Red - every time our guide drove up to check on us in our sleeper shacks one of the lines would go just as he pulled up and stopped - either crappies or walleyes.
Balsam - tipups set for bass and pike - after a period of inactivity, we'd circle with the trucks to stir them up.
The reason could be two-fold - could be the vibration agitates the minnows, making them more lively and that triggers the fish; could also be the vibration does something to the fish to trigger activity.
My theory on why it works? Fish are fairly lethargic in the winter. They sit and stare at the minnow for several minutes debating whether or not to eat it. You come driving up making tons of noise, the fish panics, grabs the minnow and darts off.
On bago when a group of us are looking for a new school of fish, we will "leap frog" past each other. The one moving will drive 100 yds from the guys fishing just to see if the noise pushes a school. If someone notices fish during that, we will hone in on that school if it seemed big enough to make it worthwhile.