State Road 518, also called Eau Gallie Boulevard, is a short but major east–west highway with a western terminus at Interstate 95 on the Florida mainland, crossing the Indian River via the Eau Gallie Causeway (and intersecting the southern end of SR 513), and having its eastern terminus at SR A1A. Most of SR 518 is located within the city of Melbourne.
State Road 518 begins at Exit 183 of I-95, and continues east on Eau Gallie Boulevard through a recently built suburban area. About 1/2 mile east of the I-95 interchange, it intersects Sarno Road, State Road 5054, and the former route of SR 518. The road continues through sparsely developed land until its intersection with County Road 509 (Wickham Road), where SR 518 continues through a denser area, passing through mostly commercial business, with residential areas not far away. At US 1, the road splits into a one way pair of Montreal Avenue and Eau Gallie Boulevard making its way to the Eau Gallie Causeway, which takes SR 518 across the Indian River. At the east end of the causeway, it intersects State Road 513, entering Indian Harbour Beach. It passes though more commercial developments for the rest of the route, where it ends at State Road A1A, just west of the beach and the Atlantic Ocean.
The road west of I-95 is referred to as the "Sarno Extension".
In 1964, the interchange between Eau Gallie and I-95 opened, which was reconstructed in 2009.
Eau Gallie Boulevard and the Eau Gallie Causeway were both named after a city that merged with Melbourne in 1969.
Originally, SR 518 traveled along Sarno Road from its western terminus at I-95 to U.S. Route 1 (SR 5), then followed US 1 (Harbour City Boulevard) to East Eau Gallie Boulevard and east to SR A1A via the Eau Gallie Causeway. Upon the completion of West Eau Gallie Boulevard in the 1970s, the sign for the I-95 exit to SR 518 changed the name of the street from "Sarno Road" to "Eau Gallie Boulevard" and SR 518 was re-routed to its current configuration.
The entire route is in Brevard County.
State Road 5054 is a major east–west highway in northern Melbourne (formerly Eau Gallie). Its western terminus is at SR 518, a half mile east of I-95; its eastern terminus is an intersection with US 1. The road is unsigned.
State Road 5054 begins at the intersection of State Road 518 and Sarno Road, with SR 5054 taking a slight southeast turn before heading straight east through sparsely developed land from the western terminus to Wickham Road. East of Wickham Road, Sarno Road serves some business, while being mostly a residential street from here to its eastern terminus at US 1.
State Road 5054 is entirely composed of a former configuration of State Road 518. When West Eau Gallie Boulevard was completed in the 1970s, SR 518 was resigned on the new road, with the portion of Sarno Road about 1/2 mile west of I-95, east to US 1 was renumbered as SR 5054. The section of Sarno Road west of the then-new West Eau Gallie Boulevard was renamed West Eau Gallie Boulevard.
The entire route is in Melbourne, Brevard County.
Traffic at selected junctions include: