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Addendum to the Phase 1 Archaeological Survey of SR 316 and SR 81 Grade Seperation Project

Author(s)
Report Number
5908
Year of Publication
2010
Abstract

This project involves the grade separation of the existing at-grade intersection of SR 316 and SR 81. The proposed grade separation would include provision of full interchange providing access to and from SR 316 to the cross road of SR 81. Interchange would be designed to accommodate the future widening.. of SR 316 from existing two general-use lanes in each direction to three lanes including a barrier separated high occupancy vehicle (HOV) lane in each direction. SR 316 currently provides four 12-foot travel lanes (two in each direction) separated by a 44 - foot grassed median. The existing right-of-way is approximately 300 feet wide. The roadway has 10-foot right shoulder and six-foot left shoulder with rural drainage. SR 81 currently provides two 11.5-foot travel lanes with four-foot outside shoulders and rural drainage. The existing right-of-way varies from 60 to 100 feet wide. The existing intersection with SR 316 is signalized. Project CSNHS-0008-00(429) would construct a full diamond interchange at the existing atgrade signalized, intersection of SR 316 and SR 81. Proposed ramp heads would be spaced 750 feet apart. Improvements to SR 81 would begin approximately 0.17 miles south of the existing SR 316/SR 81 intersection and continue northerly along SR 81 for a total length of approximately 0.35 mile. In order to accommodate the 2032 design year traffic, the bridge carrying SR 81 over SR 316 would require a six-lane bridge with two through lanes in each direction plus two left turn lanes. However at this time the Department proposes to design a four-lane bridge carrying SR 81 providing one through lane in each direction plus left turn lanes. SR 81 would taper down to a two-lane section to match existing typical section at project terminals. This proposed improvement would operate at an acceptable level of service until the year 2018 at which time this intersection would start operating at an unacceptable level of service. The proposed right-of-way width would vary from 100 to 200 feet wide. Revised Project Description: Full diamond Interchange concept was revised to a tight urban diamond interchange. Extension of project limits along SR 81, north of SR 316, by approximately 385 feet.