Addendum to Phase I Archaeological Survey of the Proposed Roundabout at the Intersection of SR 275 and CR 307/Rincon-Stillwell Road, Effingham County, Georgia

The proposed project is an addendum to the phase I archaeological survey of the proposed roundabout at the intersection of SR 275 and CR 307/Rincon-Stillwell Road in Effingham County, Georgia (P.I. No. 0009872, HP No. 131119-009) (Sipe 2015). The addendum includes extensions to the northern, southern, eastern, and western portions of the survey area where construction impacts are proposed to occur outside of the survey limits presented in Sipe (2015).

The current intersection is characterized by a two-way stop on CR 307/Rincon-Stillwell Road (CR 307), facilitated by a blinking caution traffic signal for SR 275 and blinking red light for CR 307 with no turn lanes in any direction (Figure 1). Current traffic conditions have exceeded the effectiveness of this solution and the project description outlined in the original report (Sipe 2015) proposed to construct a roundabout, measuring 200 feet at the intersection to ease congestion and improve safety. Proposed construction activities were primarily limited to the roundabout and the immediate intersection itself; however, the proposed roundabout is designed to enhance safety and improve the overall operational efficiency of the intersection. As such, the proposed project will add turning lanes to each of the roadways forming the approach towards the intersection. To facilitate this design the APE of the original project included the footprint of the roundabout itself along with portions of the approximately 100-foot wide corridor of SR 275 and CR 307 approaching the intersection. Originally, this included 500 feet of SR 275 on either side of the intersection, 400 feet of CR 307 to the north of the intersection, and 600 feet of CR 307 to the south of the intersection. The proposed addendum to this project consists of a 125-foot extension of the APE along CR 307 to the north of the intersection, an additional 200-foot extension of the APE along CR 307 to the south of the intersection, 150 feet of additional APE along SR 275 to the west of the intersection, and 30 feet of additional APE along SR 275 to the east of the intersection (Figure 2). The majority of this new area falls within the ESC established for the original project; however, the new APE does extend outside of the original survey area along the northern, western, and southern approaches towards the intersection. An additional 100-foot ESC was added to each of these new areas and the 100-foot ESC was expanded to the east to compensate for the additions to the APE in that direction (see Figure 2). All impacts proposed as a result of this project will occur within the boundaries of the existing ROW, which is depicted as the APE. No easements, temporary or permanent, are required for this project.