In Gwinnett County, I-985 begins concurrent with SR 365 at an interchange with I-85 on the southeastern edge of Suwanee. The two highways head northeast to Buford, at an interchange with US 23/SR 20. Here, US 23 joins the concurrency of I-985/SR 365.
The three routes head northeast into Hall County until they meet SR 347. In Flowery Branch they meet Spout Springs Road at the Rankin Smith Interchange. Then they enter Oakwood, and meet SR 53, which doesn't have any return access from southbound I-985/US 23/SR 365. Just after, they enter Gainesville, where they intersect SR 13. Its interchange has access to both SR 13 and SR 53. Farther into Gainesville is SR 53 Connector/SR 60. In the main part of the city, US 129/US 129 Business/SR 11 meet the concurrency. US 129/SR 11 head south toward Jefferson, while US 129 joins the concurrency through the rest of the city. Meanwhile, US 129 Business/SR 11 head north into the heart of Gainesville. Nearly later US 129 departs to the north with SR 369 on Jesse Jewell Parkway. About later, I-985 ends, while US 23/SR 365 continue north.
All of I-985 is included as part of the National Highway System, a system of roadways important to the nation's economy, defense, and mobility.
History
1920s
The roadway that would eventually become I-985 was built at least as early as 1919 as SR 13 from Buford to just northeast of Gainesville, along the same alignment as it runs today. A reconfiguration of the SR 13 and SR 15 intersection in the Baldwin–Cornelia area, caused the two routes to run concurrently between the two cities. By the end of 1926, a small section in Gainesville was paved. By 1929, US 23 was designated along the section from Buford to Gainesville.
1930s and 1940s
By 1932, US 23 was designated along the route all the way to Cornelia. In addition, the entire route, from Buford to the South Carolinastate line, was paved. The next month, US 23, and possibly SR 13 was extended south from Buford. In 1935, after a long series of improvement projects the section just south of Buford was paved. Between 1946 and 1948, US 123 entered the state, being routed on a concurrency with SR 13 between Toccoa and the state line. Prior to April 1949, US 123's concurrency with SR 13 was extended to Cornelia. During this time, US 441 was extended along SR 15, thus beginning a concurrency with SR 13.
1950s-1970s
Between 1955 and 1957, a freeway was under construction from northeast Atlanta northeast to Suwannee, paralleling US 23/SR 13. Between 1957 and 1960, I-85 was completed as far north as what is now known as SR 317, which is located just southwest of what is now the southern terminus of I-985/SR 365, and by 1966, it was completed northeast of Atlanta within the state. In 1966, SR 365 was being projected as a freeway from its current southern terminus northeast and curving around the southeastern side of Gainesville. In 1969, the whole freeway section, with the exception of the southernmost portion from I-85 to US 23/SR 20, was completed. Also, the entire completed section was designated as SR 365. The next year, the southern-most segment was completed. By 1979, the SR 365 freeway was listed as "under construction" from the northern terminus of the freeway northeast to US 23/US 441/SR 15 near Cornelia.
1980s and 1990s
Between 1980 and 1982, SR 365 was extended along the "under construction" section, but it was not a freeway. Also, US 23/SR 13 from Gainesville to Cornelia were moved onto this new highway. By 1986, the entire freeway segment was designated as I-985.
