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The lane width adjustment factor simply takes into account restricted <br />• lane width and lateral clearance. Because SH 133 on]y has ten-foot lanes, <br />the service volume will be lower than for highways with 12-foot lanes. <br />Lateral clearance, however, did not appear to be restrictive. A value of <br />0.78 was determined appropriate for the study section. <br />The truck adjustment factor is a number derived from generalized opera- <br />~- tional characteristics of trucks, considering a truck to be equivalent to <br />~ a certain number of passenger cars, depending upon terrain and conditions. <br />In relatively level terrain at level of service C, the passenger car equiva- <br />lent is 2.5. <br />Truck adjustment factors are shown in the Highway Capacity Manual for <br />-• percentage of trucks up to 20%. Reviewing data collected and presented in <br />Table 1, it is seen that truck volumes are approximately 18% of the vehicle <br />mix. As can be determined from analysis presented subsequently in this <br />report, the percentage of trucks is expected to be approximately the same <br />~- (or even slightly less) when the production level is expanded to 1.3-million <br />- TPY. This is because coal will be trucked in two shifts instead of one. <br />-. <br />For the purpose of this report, a truck adjustment factor based upon <br />_. 18% trucks was used for determining the maximum hourly volume at level of <br />~- service C. The truck adjustment factor used was 0.80. <br />The maximum hourly volume permissible on SH 133, without degrading <br />_• level of service C, is: <br />2000 x 0.38 x 0.78 x 0.80 = 474 vehicles/hour (both directions). <br />-13- <br /> <br />