The speed limit in the fog safety zone on Interstate 75 has been reduced through Bradley and McMinn counties Thursday morning.

Reports of freezing fog on the roadway has the speed limit reduced for safety. The fog has also reduced visibility for motorists.

READ MORE | 25th anniversary of I-75 fog crash

A chain reaction of crashes in 1990 near Calhoun, TN resulted in a 99-vehicle crash that injued over 40 people. That incident prompted the creation of the fog zone.