Perhaps the vehicle users could organize a campaign to restore the roadside habitat and remove the waste, or at least to decorate it sufficiently so that it doesn't appear unsightly. Since the "white" paper appears to be the primary concern of this group, perhaps users should just use camouflage TP.
A better solution would be closer regulation of traffic, possibly with a toll or permit system, and requirement that "road" travelers carry WAG or equivalent. Voluntary measures seem doomed to fail as indicated in the article, efforts have been made for years to reduce the fecal impact of travel.
The cure for a fallacious argument is a better argument, not the suppression of ideas.
-- Carl Sagan