An aggressive replacement plan to update the Illinois State Police's aging patrol vehicles has stalled following Gov. Bruce Rauner's moratorium on vehicle purchases to stem a budget crisis that has driven Illinois' credit rating to the lowest in the nation.

In the past two years, the State Police have spent nearly $8 million to put 300 new vehicles on the road as part of an initiative driven by a vehicle registration surcharge that has raised $58 million to replace State Police vehicles, reports the Associated Press.

In October, the fleet of 2,337 vehicles averaged 3.8 years in age and 62,607 miles. In 2005, a fleet of 2,285 vehicles averaged 6.2 years in age and 112,841 miles, according to the AP.

An executive order signed by Gov. Rauner earlier this year has halted new vehicle purchases, and the agency is now equipping vehicles purchased under the administration of former Gov. Pat Quinn.