Litter Survey: Status Report 2

About the report:

This report discusses the results of three series of litter pickups at twenty 0.1-mile long sites on Virginia highways 4 sites on the interstate system, and 8 each on the primary and secondary systems. This study is a continuing effort to monitor quantities of litter and is considered the best approach available short of extensive survey sampling that would require large monetary expenditures. The rationale behind the study methodology is explained in "Litter Survey Status Report 1". It should be understood that the results as discussed herein pertain to the twenty sites mentioned, and should not necessarily be generalized to apply to the entire Virginia highway system; i.e., the twenty sites are not considered a statistical sampling from which generalizations about the entire highway system can be made with stated levels of confidence. Nevertheless, it is believed that the results obtained at the twenty sites are an indication of what may be occurring on the Virginia highway systems. The primary measure used in this study to quantify litter is item count. The results indicate a rather dramatic reduction in litter from survey to survey at the twenty sites as indicated on the bar graph given on page 5 of the report. Analyses showed the reductions, in most cases, to be statistically significant at a 95% confidence level. Whether or not the items per day continue to decrease or remain at the lower levels can be answered only by future surveys. It would be invalid to compare the quantities in terms of items per day in the study to results obtained in the 1976 litter survey, since the twenty sites used in the current study were selected with certain characteristics in mind and in no way represent "average" sites. However, proportions of litter by type can be compared, and on the basis of this study it is felt that the 1976 study underrepresented paper and plastic items. Proportions by category shown in Table 4 on page 12 of the report indicate about 70% paper and plastic as opposed to the 54% reported in 1976. This difference, it is believed, is due primarily to the long time periods preceding the litter pickups in the 1976 study allowing many paper and plastic items to be removed from the sites by natural forces.

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