When it comes to quad bikes use you brain, have a look at this it will help you. There are a few things that make this safer firstly, lock the ramps with pins this will stop the ramps falling over. Park ute so its near embankment so the ramps are not steep, this will calm the rider down if they nervous. Go slow and use a spotter to give directions if needed. Do all this you it will be better for all people involved, less accidents.
Quad bikes can rollover very easily watch the video you can see how unbalanced they are. Use you body to shift your weight to minimise the chance of rollovers.