Most Illinois highways — but not many in the Chicago area — will increase their speed limits to 70 mph after the new year following a new law signed this August.
Most areas that will see speed limits raised from 65 mph to 70 mph are outside the Chicago metropolitan area, according to a map released Friday by the Illinois Department of Transportation.
However, short stretches of I-55 and I-80 southwest of Joliet, and I-57 south of Park Forest in Will County will see the 70 mph bump, as will I-88 west of Aurora in Kane County. In Lake County, speeds on a stretch of I-94 between Waukegan and the Wisconsin border will also increase.
The law also includes a provision that allows police to charge drivers with excessive speeding for going more than 26 mph over the posted limit. The previous threshold had been slightly higher, at 31 mph.
Once the new law goes into effect, drivers will be able to cruise at 70 mph on roughly 87 percent of the state’s interstate highway system. Just 28 percent of the Illinois Tollway’s 286 miles of roadway will see the speed limit increase.
Roughly 900 new road signs — costing $200,000 to make and install — will arrive in early January. Until then, drivers should obey all posted speed limits, state traffic officials said.