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When in 1997 Caltrans published its study on alternatives, California Roadsides: A New Perspective, several alternatives were chosen as viable and affordable to varying degrees. Caltrans ranked six of eighteen according to cost per area, length of life cycle, cost over 20 years and potential amount of herbicide use that could be reduced. Unfortunately, the agency has not implemented any of these options on a broad scale - even though most are affordable, perhaps even cheaper to use than herbicide application, and also are immediately available for implementation.
Of these, the most cost-effective and environmentally beneficial are:
* reduced-width clear strips -- which means simply spraying a narrower swath of herbicide along roadsides. Although Caltrans has boasted that it has reduced clear strips, close inspection shows that the agency doesn't know what its applicators are actually accomplishing in the field. This extremely cost-effective alternative could reduce herbicide use by up to 15%.
* preferred vegetation -- as described in the Competitive Vegetation section of this report, this is somewhat more expensive to set up than other methods but pays for itself as subsequent years of low maintenance add up. Caltrans estimates a ten-year life cycle, but other agencies say that twenty or thirty years is more realistic. Up to 15% of current herbicide use could be reduced (although Caltrans spraying in landscaped areas is high enough that this alternative could actually reduce herbicide use by 40+%).
* water-retention areas -- would provide important wildlife habitat and reduce herbicide use up to 5% in a five-year life cycle. Not expensive, but not cheap either, the intrinsic ecological improvements of this option would figure into the payoff.
* organic mulches -- could easily be used much more intensively than it is now. Relatively inexpensive as Caltrans has estimated it, its value may increase if used in combination with corn gluten (see Corn-ucopia section) to extend its life cycle, which Caltrans figures would last for four years. Herbicide reduction is estimated to be up to 10% with this method.
All told, just by using these four methods, Caltrans could, by its own figures, reduce herbicide use by 45%. What is the agency waiting for? It's time for a change!
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