2006-06-12_REVISION - M1978314 (2)

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April 25, 2005 Mr. Carl Luppens Page 2 of SH 134. If the CDOT volumes are accurate for the intersection, the evening peak hour traffic counts represent a low percentage (5.4 % south of SH 134 and 8% to the north). CDOT statistics show 15% for the design (peak) hour south of SH 134 which would increase the peak hour volume from 75 vph to 210 vph. Based on 9°h design hour north of SH 134 (CDOT), the peak hour volume increase would be smaller (72 vph to 81 vph). During portions of three hours when we conducted our field visit, we observed five separate gravel trucks (10 trips) on CR 5. Three of these trucks were observed to be turning either to or from the south on SH 131. (The origin/destination of the other two was not observed). The various materials we have reviewed imply that the mine has historicalty produced an average of 10,000 to 20,000 tons per year. Last year the tonnage was approximately 100,000 tons with 80°k of that for one job. The LSC report calculates 43 daily truck trips for an average month at the proposed 100,000 ton per year level. April would seem to be a relatively low volume month, and 10 truck trips in three hours would appear to be a relatively high volume for an activity level of approximately 20,000 tons per year. The LSC report calculates mine traffic based on aggregate hauling and employee/vendor trips. The permft request to Routt County states that there will also be a concrete plant and an asphalt plant at the ske. The 100,000 ton level may include trucks hauling these more finished products but doesn't appear to include the delivery of raw materials (cement and asphalt), which would also be in large trucks. The growth rate of 2.0°h per year over 20 years agrees with the growth forecasts shown by CDOT for SH 131. However, it appears that a smaller growth rate in background traffic was assumed for CR 5 (see LSC Figure 7). Using the CDOT growth rate since R is the most relevant forecast available, the background traffic on CR 5 would increase to approximately 125 vpd in the future from the current 83 vpd. The LSC study increased truck volumes by a factor of 2.3 to account for the impact of heavy trucks for capacity analysis calculations at the intersection of SH 131 and CR 5,. This is in line with truck factors included in the 2000 Highway Capacity Manual (1). Table 2 of the LSC report shows that adequate levels of service (LOS B) will be maintained at this intersection in the future. SH 131 is under the jurisdiction of the CDOT which has adopted the State Hiahwav Access Code (2) for all state highways. It provides guidelines and requirements for existing and new access points. Since the increase in traffic volumes at the intersection will be significant, a new access permit from CDOT is required. Routt County is involved in the process since CR 5 is a public roadway under its jurisdiction. The LSC report concluded that no auxiliary turn lane improvements are necessary at this intersection due to low through traffic volumes on SH 137. Although a review of accident statistics compiled by CDOT shows that there are no apparent accident problems currentty at the intersection, we are concerned about safety at this intersection with the increased number of trucks. In spite of the low volumes, CDOT has the discretion to require an auxiliary turn lane if it would be a benefit to safety and operation of the roadway. In the future, information in the LSC report (March 2005 -Table 1) shows that 45 trucks per day are forecasted to be fuming left from CR 5 to northbound SH 131. These trucks would be heavily loaded and would not be able to accelerate up to highway speeds very quickly. A left turn acceleration lane should be seriously considered for this movement. The existing cross section of SH 131 has approximately 25 feet of pavement for the two traffic lanes with 3-foot gravel shoulders on each side. Although the