I-985 is also known as the Sidney Lanier Parkway, after the musician and poet, and is also designated as unsigned State Route 419 (SR 419).

I-985 is the highest-numbered spur route of a north–south Interstate and is second only to I-990, which serves the town of Amherst, New York.

In Gwinnett County, I-985 begins concurrent with SR 365 at an interchange with I-85 on the southeastern edge of Suwanee.

In Flowery Branch, they meet Spout Springs Road at the Rankin Smith Interchange, named after the respective businessperson.

Then, they enter Oakwood and meet SR 53 (Mundy Mill Road), which does not have any return access from southbound I-985/US 23/SR 365.

In the main part of the city, US 129/US 129 Business (US 129 Bus)/SR 11 (Athens Highway) meet the concurrency.

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.

In addition, the entire route, from Buford to the South Carolina state line, was paved.

[21][22] In 1966, SR 365 was being projected as a freeway from its current southern terminus northeast and curving around the southeastern side of Gainesville.