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lower volumes. The screenline results are summarized in Table 8. Locations with <br />counts so low that they are less than the evaluation criteria are shown as "NA." <br />All screenlines and the total of all screenlines are within acceptable standards. It <br />should be noted that not all crossings of a screenline had count volumes. <br />Therefore, there may be some variations that are not completely explained by <br />this table. It is felt that all screenlines are within acceptable ranges. <br />Table 8 ~ <br />Screenline Analysis <br />No. NAME Tot Vol Tot Count % Deviation %Allow <br />1 CleElum 128 76 68% NA <br />2 West of Ellensburg 69 55 25% NA <br />3 North of Ellensburg 116 .... 84 38% NA -i:c <br />4 West Ellensburg 3207 2388 34% 47 % <br />5 North Ellensburg 474 442 7% 70 % <br />6 South of Ellensburg 488 451 ~ 8% 69% <br />7 Central Ellensburg 5041 5522 I -9% 33% <br />8 EW Central Ellensburg 3184 2841 12% 43% <br />9 East of Ellensburg 577 629 -8% 67% <br />Total .. 13284 l 12488 6% 23% <br />~ C <br />Scattergram Analysis <br />Several analyses of scattergram plots showing the correlation between traffic <br />count observations and model volumes were conducted. Figures 6 and 7 show <br />comparisons for ALL traffic munts and counts on just Freeways, Ramps, and <br />Principal and Minor Arterials, respectively. Typical standards are usually <br />compared on roads classified as Principal Arterial and higher classifications. <br />More deviation is expected when analyzing lower classification facilities such as <br />collectors and local roads due to the variation in traffic count data and the lower <br />volumes. Both figures show link ground counts on the X axis and assigned <br />volumes on the Y axis. On the green 'goal' line the assignment volume is equal to <br />the ground count. The red linear 'regression' line shows the best straight line <br />estimate of the assignment volume for any count. The blue 'allowable' curves <br />show the maximum allowable errors according to the graph discussed from <br />NCHRP 255. In both graphs there is one significant outlier. This is the <br />westbound I-90 on-ramp at Cascade/University Way. This is an older count and <br />Kittitas County, Washington Transportation Model-May 2009 Page 41