SPRINGFIELD — Drivers hoping to legally travel faster on most Illinois interstate highways may have to wait a little longer because of the recent winter storms.

The Illinois Department of Transportation, or DOT, had hoped to install an estimated 900 new 70-mph speed limit signs by Jan. 17.

But the heavy snow and subzero temperatures that descended on the Land of Lincoln kept the sign-switching crews busy with other tasks.

"Statewide, there has been a delay in getting those signs up," DOT spokeswoman Paris Ervin said Friday.

Beginning Jan. 1, a new state law moved the speed limit on rural interstate highways up from 65 to 70 mph.

But officials said drivers should not begin traveling at the higher speed until the new signs are posted, which should happen by late this month.

The DOT had 1,755 trucks assigned to snow duty across the state, and nearly 3,700 full-time and part-time employees available to clear roads. Crews spread more than of 70,000 tons of salt on Illinois roadways.

"The recent winter storm was top priority for our operations crews, but now that the weather has improved, starting next week, we hope to get more 70- mph signs erected throughout the state," Ervin said.

Employees were able to install some of the new signs. For example, Ervin said, crews were installing them along Interstate 55 in Logan County in the central part of the state.

Once all of the signs are up, drivers will be able to go 70 mph on nearly 90 percent of Illinois' interstate highways.

Changing all of the signs will cost an estimated $200,000.