Agenda - 03-20-2001-9b - Laserfiche WebLink

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S MEMORANDUM TO: County Commissioners John Link, County Manager COPIES: Paul Thames, PE, County Engineer Phil Post, PE FROM: Craig Benedict, Planning Director DATE: March 13, 2001 SUBJECT: Grading/earthwork far Class A Private Road versus State Maintained Road at Sunrise Springs subdivision After discussion with Paul Thames and his analysis of the roadway plans for the Sunrise Springs subdivision, the following information is provided. The question is posed... if providing a road using the construction standards for Orange County's Class A private road as opposed to NCDOT's standards for the proposed state-maintained road would significantly lessen the grading required or the impacts of that grading. Far the purposes of this analysis, there are only three points of difference between the two standards that would have any effect on the outcome of the analysis: 1) in cut sections; 2) roadway grades; and 3) length of vertical curve. In conclusion, it is my opinion that minor earthwork reduction (approximately 4' less cut) gained by changing the design standards for Sunrise Springs Road from those of a public road to those of a Class A private road are generally offset by other negative consequences of: a) steeper slopes -more erosion potential, b) less vertical curve - increase in driver/pedestrian hazard potential, c) no significant difference in noise attenuation based on the minor adjustment in cut, d) private road would direct more drainage to internal drainageway versus spreading runoff to multiple areas, and e) more difficulty in the maintenance of a gravel roadway. The minor reduction in cut and fill could only be accomplished if a variance was permitted to allow a 12% grade versus the typical 9% grade for a private road. In the absence of the variance the cut and fill for the public or private road would be significantly similar. e If I may provide additional information on this matter, please advise.