Leave no trace.. on the trail or on the lawn.
To tie-in my seeming OT posts with the photos of the cool rides above-
Motorized trike vehicle design moved to using two wheels forward instead of one because of dynamic directional stability concerns, but the basic relationship is the same as illustrated in the drawing in my previous post above. The difference is that with vehicles the concern is mostly about dynamic stability, rather than static stability. If static stability were to be that bad, the thing would just fall over while parked.
Dynamic stability has to do with the change in stability as the center of gravity shifts around. When underway, the greatest center of gravity shift to be most concerned about occurs during strong braking. When braking the center of gravity shifts forward, and with a single wheel forward design, directional stability suffers. If the rider needs to swerve while braking hard there is a very high risk of tipping over in a direction away from the turn, which is why offroad 3-wheel ATVs were discontinued years ago and replaced with 4-wheel designs.