2006-06-12_REVISION - M1978314 (2)

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April 25, 2005 Mr. Carl Luppens Page 3 speed limit at this intersection and through Toponas is 45 mph, this roadway width does not leave room for evasive maneuvers if a car on SH 131 suddenly comes upon a slowty accelerating truck. The close distance to the nearby intersection of SH 131/SH 134 (approximately 1,100 feet) would also be a factor in the design. County Road 5 Improvements The McLaughlin Memorandum of February 25, 2005 requests a number of improvements to existing CR 5 and the two bridges crossing Egeria Creek. Our field trip to the site confirms that these improvements will be necessary to properly handle the level of activity that is proposed. We have also conducted extensive research concerning gravel roads and when there is a need to pave them. The LSC report (March 2005) forecasts a total daily volume of approximately 425 vpd on CR 5. If our calculated increase in background traffic is factored in, this volume could be up to 450 vpd. This volume is based on a truck equivalency factor of 2.3. While this factor is appropriate for traffic operations analyses, it does not adequately account for the difference in weight between cars and trucks, and the impacts that heavy trucks have on roadways. Our research concerning gravel roads has revealed the following information: • Colorado Department of Public Health and Environment Regulations (3) require that particulate (dust) control measures be used on unpaved roedways which have traffic exceeding 200 vehicles per day in attainment areas or 150 vehicles per day in nonattainment areas. Our assumption is that this rural part of Routt County is an attainment area, so the 200 vpd standard would apply. A survey of Departments of Transportation in the United States and Canada conducted by the Alaska Department of Transportation (4) found that: "Most respondents felt that average annual daily traffic volumes and the desire to reduce maintenance costs were the two most important reasons for paving an unpaved road:" This report also states that "There are at least two reasons to anticipate a reduction in road maintenance costs after paving. First, grading costs are eliminated. Among other problems, gravel roads are prone to washboarding and the loss of fines over time. Exactly how quickly such problems occur depends on traffic and weather. But, to be maintained in reasonably good condition, gravel roads must be graded periodically, and the expense can be significant. Repaving a road is more expensive than grading but occurs less frequently so that often there is a net cost savings, according to ADOT official. Second, the time required for snow removal is reduced. Graders are used to plow gravel roads. In order to minimize gravel removal during plowing, frequent blade adjustments are required. On paved roads trucks with floating blades that automatically adjust to the contours of the road can be operated at higher speeds, thus can plow more miles per day, than graders." • Concerns about maintenance costs are also addressed in an Iowa publication (5): "Maintenance cosUmile of gravel roads is greater than the maintenance cosUmile of bituminous roads when the ADT is above 100. Also the maintenance cosUmile of gravel roads increases considerably when the ADT is greater than 200. "