Next to them, or in front of them. Of course, that precludes using any public road, so whatta ya gonna do? Problem with debris on the road is the unpredictable response from other drivers, who often change lanes rapidly, without warning, usually without looking. Or the fine folks that pretty much stop on the road (Interstate or not, doesn't matter). Unfortunately the 3 second following distance is sometimes inadequate, especially if the cage in front shreds the debris and launches it air-born, which I've seen on more than one occasion.