UPDATE: Repairs to I-85 will take several months, GDOT Comissioner Russell R. McMurry said at a press conference. Three sections on both northbound and southbound I-85 will have to be replaced, as well as support columns.

Officials do not have a definite timeline or a cause for the fire yet.

The PVC piping and fiber optic cables caught fire underneath the interstate, but those materials do not catch fire without an outside source, the commissioner said.

The piping had been stored underneath I-85 since 2006 or 2007 and storing excess construction materials underneath overpasses is not unusual, he said.

Motorists are flocking to 285. The amount of motorists on the perimeter interstate is up 50 percent, McMurry said, and use of other alternative routes is up 25 percent.

GDOT will continue to make adjustments and release new detours.

Keith Parker, the general manager of MARTA, said at the press conference that ridership and sales are up. They are seeing spikes on suburban routes and park and ride lots are filling.

Original story:

A fire that collapsed a portion of I-85 northbound will affect roughly 250,000 motorists who use the interstate each day. The fire has caused a three-mile section of the interstate to be closed indefinitely in both directions.

The Georgia Department of Transportation is encouraging people to either work from home or use public transportation. GDOT also released two maps detailing alternative routes for people who must drive and is encouraging motorist to be patient and check Georgia 511 for traffic information.

In the city of Brookhaven, the Regional Traffic Operations Program is implementing longer throughput traffic signal cycles on Buford Highway and Peachtree Road, according to a city press release. Both roads are state routes. This may cause delays in Brookhaven neighborhoods that directly access these roads.

GDOT alternative routes:

There was thought that rail lines could have been damaged by the fire, but MARTA is reporting all bus and rail lines are running and additional service has been added to accommodate extra passengers. MARTA is reporting bus lines 15, 27, 39 and 47 are experiencing delays due to heavy congestion.

Although the fire occurred underneath an elevated portion of I-85 North, I-85 South is also closed indefinitely for repair. There are no estimates yet on how long the repairs will take.

“At this point, I don’t have the ability to tell you how long it will take to restore I-85. Repair to this essential interstate is a top priority and we will be doing everything within our power to expedite the rebuilding process,” GDOT Commissioner Russell R. McMurry said in a statement.

The Georgia Department of Transportation has closed the ramps on I-85 southbound to Chamblee Tucker Road, Shallowford Road, Clairmont Road and North Druid Hills Road indefinitely.

The fire began in an area used to store construction materials, equipment and supplies, but its unclear what caused the materials to set fire.