A 2007 engineering study for SIU 5 identified then-current conditions along the Pennyrile and Western Kentucky parkways. The report identified seven overpasses that fell short of the minimum vertical clearance necessary for Interstate Highways. An additional 28 mainline bridges were identified for not meeting the minimum horizontal clearance of . Most—if not all—of the aforementioned bridges were built during construction of the parkways in the 1960s and are nearing the end of their serviceable lifespans and due to be replaced. The main issues concerning the 16 interchanges in SIU 5 were short acceleration/deceleration lanes (the average is while Interstate standards mandate ) and tight curve radiuses at interchanges with loop ramps. A particular challenge was reconfiguring the cloverleaf interchange between the Pennyrile and Western Kentucky parkways in Nortonville to accommodate the future movement of traffic primarily between points north and points west.
