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• and recompacted to at least 95% of the standard Proctor density determined in accordance with ASTM D698. The new subbase gravels and base course materials placed on [he roadway shoud be compacted to a[ least 95% of the maximum modified Proctor density at or near the optimum moisture content, determined in accordance with ASTM D1557. The base course and subbase gravels shoud be approved by the soils engineer, prior to placement. We recommend that the road base gravels placed on the roadways meet [he requirements far Class V or VI base course in accordance with the Colorado Department of Transportation specifications. [n addition, the subbase gravels should meet [he requirements for Class II or Class IiI base course. Drainaee: The collection and diversion of surface drainage away from the roadway area is extremely important for satisfactory performance of the roadway. The design of surface drainage features should be carefully considered to remove all water from all roadway areas. In addition, the maintenance of all drainage structures shoud be conducted periodically to ensure proper performance. We recommend that the new gravel surface be constructed with a crown or super elevation of at least 2 percent. Limitations: This report has been prepared in accordance with generally accepted soil and pavement engineering practices in this area for use by the client for design purposes. The conclusions and recommendations submitted in this report are based upon the assumed traffic loadings and the data obtained from the test holes advanced along the subject roadway. If during construction, soil and • ground water conditions appear to be different from those described herein, this office should be advised at once so th eevaluation of the recommendations may be made. We recommend [he on- site observation of te~ubgrade proofrolling, gravel placement and compaction by a qualified soils engineer. ~ ~ ~] Sincerely, Brian D. Len, P • -rRaco