Second, the characteristic weed growth of the road edge tends to stabilize the trash and to fix it in an optimum array for mechanical reduction when the road edge is mowed. Landfill bagged trash is absolutely configured in a mode that prevents further reduction. Mechanical reduction through mowing enhances the biodegradability of many products on the road edge. Third, the configuration of light trash, particularly expanded foam and PET type plastics, in the road edge allows for eventual alternate landfilling of these products through the drainage system. We must continue to understand that the dendritic pattern of our roads is a hydraulic parallel to the perennial streams of the watershed.
Most roads generate two miles of intermittent stream course for every linear mile of road.
Roadways are the most important unacknowledged stream system in our urban and agricultural areas. Storm drainage along the road edges serves to separate the low density foam and plastic products from the bottles and cans. Since the foam floats whether entire or mulched, the storm drainage will carry the foam away from the road edge for eventual disposal via the natural stream system that the road drainage eventually intersects. We should note the importance of the sediment deltas at the heads of lakes and the role of vegetation, particularly cattails, in anchoring the sediments and in serving as a vertical screen for entrapping the floating trash. A large and effective example of such a delta can be observed beside I-24 south at the Haletown exit immediately south of the Nickajack Bridge.