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Normalizn~on Technique <br /> <br />Two survey results indicated that data normalization ~s desirable for this <br />study: 1) Some data groups have significantly higher percentages of return <br /> than others, with the highest percentages coming from groups which <br /> represent smaller portions of the 24-hour traffic volume (AADT), <br /> i.e., AM Peak - 66% return, 13% of AADT, Mid-day - 49% return, 58% <br /> of AADT. This situation would tend to over or under emphasize the <br /> respective data groups. <br /> <br />2) Plotting the response to question 5 with respect to time and <br /> comparing the graph to the 24-hour distribution of traffic also <br /> indicated that the mid-day was under-represented. <br /> <br />The normalization technique employed adjusts the effect of each sample group so <br />as to not unduly influence the aggregate result. <br /> <br />First, the 24-hour distribution of traffic w~s plotted. See the graph on the <br />following page. Next, the peak periods were identified and the percentage of <br />the 24-hour traffic included by each peak period ~s determined. The weekday <br />raw data was combined into 3 time of day groups, i.e. A1 + C1 ~ AM peak, A2 & <br />C2 ~ off peak, A3 + C3 = PM peak. Next, the percent return by group w~as <br />determined as a percentage of returns. A factor was determined to reconcile <br />the percent return by group to equal the percent of 24 hour traffic the group <br />was to represent. This factor was applied to the raw data and the normalized <br />weekday aggregate percentages were calculated. <br /> <br />Note: 1984 AWDT = 31,500 <br /> 866 returns ~ 2.7% <br /> <br /> <br />