The speed limit is going up on more than 90 miles of metro Atlanta interstates, but the Georgia Department of Transportation says only where it's safe.

DOT spokeswoman Natalie Dale tells WSB "Several stretches of the metro area are being raised from 55 to 65 and a handful of areas are being raised from 65 to 70."  Dale says they've done numerous studies to determine where to raise the limit.  Those studies take into account congestion and sight distances.

She says "You can rest assure we'll never be raising the speed limit on the downtown connector to 70 miles per hour."

Speed limits will be more in line with what people currently drive.  Dale says "We found in these areas drivers were already going about 5 mph over the posted speed limit."  She says "We're working to harmonize the max speed with what motorists were already comfortable going."

The changes are taking place all over metro Atlanta.  Some areas include I-85 in Gwinnett County starting at the Dekalb County line, I-75 in Cobb County and I-75 and I-85 in south Fulton County.

Some of the new speed limit signs are already up.  Others are covered with plastic bags.  The DOT hopes to have all the signs up by February 1.  Until the signs are up and uncovered, Dale says you should continue driving the posted speed limit.

State lawmakers approved the higher speed limits last year.