Fourth Addendum Phase I Archaeological Survey for an Interchange Improvement at Interstate 75 and County Road 274/Bellville Road, Lowndes County, Georgia

CR 274/Bellville Road is functionally classified as a rural major collector and is presently a two-lane rural facility with an existing speed limit of 45 miles per hour (mph). At this interchange, I-75 is classified as a rural interstate with a diamond interchange. The proposed project consists of the replacement of the existing bridge over I-75 and redirection of the ramp termini into a roundabout configuration. The vertical alignment of the proposed bridge will be improved to match the 45 miles per hour (mph) speed of CR 274/Bellville Road. The roundabouts and approaches will be designed to 25 mph. Presently, the typical sections for the bridge and CR 274/Bellville Road are rural sections with paved outside shoulders. The proposed typical section for CR 274/Bellville Road will be a rural section with a 12-foot through lane in each direction, a variable width flushed or raised median, and paved outside shoulders. The proposed typical section for the CR 274/Bellville Road approaches to the roundabouts will be an urban section with a 16-foot through lane in each direction, a variable width raised median, and 16-foot outside shoulders that include sidewalks and curb and gutters. The proposed 22-foot single lane roundabouts with variable width truck aprons at each intersection of CR 274/Bellville Road with the on- and off-ramps will have an inscribed circle diameter (ICD) of 155 feet and urban shoulders. The proposed bridge will consist of one 20-foot through lane in each direction, a 6-foot raised median, and 5.5-foot sidewalks. The proposed bridge will be offset 24 feet to the south of the existing location to accommodate staging of construction. The bridge will be lengthened to 270 feet to accommodate any future widening of I-75 to eight lanes. Due to the increased span length, the height of the proposed bridge will be 2 to 3 feet higher than the existing bridge to compensate for the extra bridge deck depth while maintaining minimum clearance requirements over the interstate. The center of the bridge roughly divides the project limits in half, such that approximately .30 mile of the project is west of the bridge and .30 mile is east of the bridge. The project will extend these distances on both sides of the bridge along CR 274/Bellville Road due to the minimum spacing distance requirements for limited access roads, the required geometric tie-ins, and to accommodate staging. Additional limit-of-access will be required along CR 274/Bellville Road to comply with current policy.