Автомагистраль IL 336 в западном Иллинойсе: история и перспективы развития.

State highway in western Illinois, US

Illinois Route 336 (IL 336, also known as the Thomas A. Oakley Memorial Highway) is a four lane freeway/expressway combination that serves western Illinois. It is also used by the Illinois Department of Transportation (IDOT) as a part of Federal Aid Primary Highway 315 (FAP315) to refer to a future project connecting the cities of Quincy and Peoria via underserved Macomb. As of early 2018, the highway extends north from its starting point in Fowler (near Quincy) where U. S. Route 24 (US 24) and Interstate 172 (I 172) intersect, to US 67 just north of Macomb. IL 336 is 80 mile (129 km) long.

For almost its entire length, IL 336 is a four lane divided expressway without property access, but has many at grade intersections with sideroads. The only interchanges currently built on IL 336 are with US 136/IL 94/Hancock County Road 1500 in Carthage, IL 61 at Mendon, and US 136 west of Macomb. Six years later, it was eventually extended again to IL 96 near Hull. By 1991, a freeway connection between IL 96 and IL 100 was finished; initially designated as part of US 36. Since 1995, part of US 36, from Springfield to south of Quincy, was cosigned with I 72. As a result of this change, IL 336 from Fall Creek at the current junction with I 72, north to US 24 near Fowler, was renamed from I 72/IL 336 to simply I 172. The upgrade of US 36 to Interstate standards provided Quincy with a much needed regional freeway. I 172 is a non chargeable Interstate Highway, inasmuch it was built entirely with state funds designated as the original IL 336, until it received its I 172 designation. That same year, IL 336 was extended north to IL 61 at Mendon. By 2010, it was extended again to follow US 136 & IL 94, leave US 136 & IL 94 near Tennessee and Carthage respectively, and then end at US 136 west of Macomb. It was later entirely designated as part of the Chicago–Kansas City Expressway (IL 110). In 2018, the Macomb Bypass, signed as IL 110 and IL 336, opened to traffic as a 2 lane road between US 136 and US 67.

IDOT launched a series of studies to help facilitate access to west central Illinois, colloquially named Forgottonia for the lack of highways through the region. Currently in progress are upgrades (to a four lane expressway) of US 67 from US 34 in Monmouth (near Galesburg) south to Macomb, and US 67 from Macomb south to Alton, near St. Louis, Missouri. Also under way is a similar upgrade of IL 336 from Quincy to Macomb. The Peoria to Macomb study involves an eastern link from Macomb to the Peoria area alongside existing US 136. The corridor being studied runs from US 67 east to I 474, and has been studied since the 1950s by Illinois and federal agencies as a potential link between Chicago and Kansas City, Missouri, the Chicago Kansas City Expressway. As of May 2006, the corridor study had identified two alternatives for IL 336. The route would be a limited access freeway for a few miles outside of Macomb to Bardolph, and again for a few miles outside of Peoria, east of Hanna City. For either alternative, IL 336 would be constructed as an expressway between Hanna City and Bardolph. In Illinois, an expressway allows partial access to the highway, with direct access to the expressway from private residences and fields, while retaining interchanges and frontage roads for businesses and arterial state routes.