Interstate 285 - Route Description

Route Description

It is eight to 12 lanes wide, with the northern part from I-75 to Georgia 400 to I-85 the most heavily traveled. One segment of the highway near Spaghetti Junction (a large, flyover highway interchange northeast of Atlanta) with Interstate 85 widens to 18 lanes, including collector-distributor lanes. Exits are numbered clockwise, starting at the southwestern-most point at I-85, and ending just east of there where it meets I-85 again near Hartsfield-Jackson Airport.

Between I-85 and I-20 in southwest Fulton County, I-285 is designated as the "Bob A. Holmes Freeway", where I-285 heads north, and has an interchange with the Langford Parkway. Between I-20 in northwest Atlanta and I-75 near Cumberland Mall, it is designated as "James E. 'Billy' McKinney Highway" as it continues north, and starts to curve to the east just west of the I-75 interchange.

The northern portion of I-285, east of the "Cobb Cloverleaf" (I-75 junction) to "Spaghetti Junction" (I-85 junction), is frequently referred to as the Top End Perimeter in traffic reports, especially by Captain Herb Emory (ABC affiliate WSB-TV and WSB AM) and Jason Durden on WSB-FM. This section, which includes an interchange with Georgia 400 at exit 27 (frequently cited as the most dangerous intersections in Atlanta), is one of the busiest freeways in the United States, handling about 250,000 cars per day and crossing through three counties. Through that stretch, the freeway expands from six or eight lanes to between ten and fourteen lanes.

Much of Atlanta's high-end commercial real estate has developed along I-285, particularly at the northwestern I-75 and the Georgia 400 junctions. Notable buildings include the 35-story King and Queen towers in the Perimeter Center business district and the Cobb Galleria complex in the Cumberland/Galleria area.

East of the Spaghetti Junction, I-285's direction switches from east to south, as it connects with the Stone Mountain Freeway at exit 39, and intersects with I-20 at exit 46, where I-285 starts to curve towards the southwest. At exit 52, it intersects with Interstate 675, and heads straight west after the intersection with I-75 near the Hartsfield-Jackson Atlanta International Airport.

A portion of the section between I-75 and I-85 on the south side of I-285 has been bridged with a new runway and taxiway of Hartsfield-Jackson Atlanta International Airport, the only interstate in the nation to a have an underpass on a runway (underpasses for taxiways do occur elsewhere). Computer animations were developed prior to construction to simulate a jumbo jet touching down on the runway from a driver's perspective. The entire highway within the tunnels is outfitted with stopped-vehicle sensors and fire detectors. Two electronic signs on either side of the tunnels can warn drivers if the tunnel is closed in an emergency. For 1.21 miles (1.95 km) in the southwest corner, I-85 occupies the median of I-285, yet the roadways remain separate.

Heavy trucks traveling through (but not into) Atlanta are required to bypass the city on I-285, as there is a well-signed and heavily enforced ban on through truck traffic along I-75, I-85, I-20, Georgia 400, and many other major Atlanta thoroughfares. As with highways just outside I-285, trucks are also prohibited from the far-left one or two lanes (except where there are left exits open to trucks).

The complete circumference of I-285 is covered by Georgia NaviGAtor, Georgia's intelligent transportation system (ITS). One-hundred fifty-three CCTV traffic cameras, twenty-six electronic message signs and traffic-detection sensors have been installed in phases between 1999 and 2010 by Georgia DOT. Additionally, ramp meters are present at nearly all entrance ramps onto I-285, with the exception of the southeast section of I-285 and the major freeway-to-freeway connection ramps.

To many residents of Atlanta, the Perimeter defines a useful boundary to separate metro Atlanta's core from its surrounding suburbs. People distinguish a location as being inside or outside the Perimeter, sometimes abbreviated as ITP and OTP, a recent local neologism. This was also the rough boundary chosen by BellSouth for separating landline telephone exchanges in suburban area code 770 from the existing area code 404 in 1995.