Ferry Road). Just over later, it crosses the Savannah River into South Carolina and the city limits of North Augusta. South Carolina I-520 curves to the north-northwest, to an interchange with US 1/US 78/US 278 (only signed as "US 1"). The highway curves back to the north-northeast and has an interchange with South Carolina Highway 126 (SC 126; Clearwater Road). During a slight westward shift is an interchange with US 25/SC 121 (Edgefield Road). Just north-northeast of there, I-520 meets its eastern terminus, another interchange with I-20. Named portions In Georgia, I-520 is known as Bobby Jones Expressway for golfer Bobby Jones. In South Carolina, it is known as Palmetto Parkway for the sabal palmetto, the state tree. Between exits 2 and 3, the highway is known as the Deputy James D. Paugh Memorial Highway after a Richmond County sheriff's deputy who was killed at exit 3 when responding to reports of a gunman who was shooting at passing cars. I-520 loses its state route designation in South Carolina, as that state does not co-number its Interstates with state highway numbers. History The highway that would become I-520 was under construction between May 1963 and January 1966 from its western terminus to just south of the US 1/SR 4 interchange in Augusta. Also, it was proposed to be an extension of SR 232, at least as far as US 25/SR 121. In 1966, the highway was open and signed as SR 232 from I-20 to Wrightsboro Road. It was under construction from US 1/SR 4 to Doug Barnard Parkway. In 1974, SR 232 was open from Wrightsboro Road to US 1/SR 4. In 1977, the highway was redesignated as I-520. The next year, it was open from US 1/SR 4 to Doug Barnard Parkway. In 1986, the highway was under construction from Doug Barnard Parkway to SR 28. In 1998, this segment was opened. The next year, it was proposed to be extended to the South Carolina state line. In 2004, this extension was opened. In 2010, the highway was extended to its current eastern terminus in the northern part of North Augusta. In January 2015, of I-520 were expanded to three lanes in each direction after work started in February 2012 for a cost of $33 million. Exit list In accordance with MUTCD guidelines for auxiliary Interstates, exit numbering is continuous across the state line and does not reset.