Illinois Route 336

Illinois Route 336 is a state highway corridor in western Illinois linking parts of the Quincy area with communities toward Macomb and the Tri-State region near Burlington. The corridor serves as a component of regional transportation networks connecting Quincy, Illinois, Hancock County, Illinois, Adams County, Illinois, Warren County, Illinois, Henderson County, Illinois and facilitating access to U.S. Route 24 and U.S. Route 67 corridors. It functions as an arterial route for freight movements associated with river ports on the Mississippi River, agricultural traffic from Illinois River Valley counties, and commuter flows to educational institutions such as Western Illinois University.

Route description

The corridor begins near the Quincy, IL metropolitan area and proceeds northeast through a mix of rural landscapes, small towns, and industrial nodes. Along its alignment the highway intersects with federal routes including U.S. Route 24 and U.S. Route 67 as it approaches the Hannibal–Quincy region, which connects to the Mark Twain Lake recreational area and the Mississippi River. The alignment traverses the agricultural plains of Adams County, Illinois and crosses tributary streams that feed the Illinois River watershed. Communities served by the corridor include Camp Point, Illinois, Bowen, Illinois, Paysons, and Macomb, Illinois suburbs, providing links to regional centers like Quincy Senior High School employment zones and manufacturing facilities connected to the Chicago–Kansas City Expressway and the Great River Economic Corridor. The route’s pavement structure accommodates semi-truck traffic destined for grain elevators, ethanol plants, and intermodal transfer points that tie into St. Louis and Chicago freight markets.

History

Planning for a modernized highway corridor in western Illinois arose from mid-20th century rural development initiatives and increasing agricultural export demand via the Mississippi River ports. Early alignments followed existing state and county roads serving towns such as Payson, Illinois and Bowen, Illinois, with successive upgrades undertaken to improve safety and capacity. Funding and political support involved elected officials from Adams County, Illinois and representatives connected to statewide transportation planning bodies. Construction phases advanced incrementally: initial segments were improved to arterial standards, later expanded with bypasses around population centers influenced by precedents set by corridors like the U.S. Route 67 upgrades and the Chicago–Kansas City Expressway. Over time, the corridor acquired design features—lane widening, shoulder enhancements, and grade separations—reflecting engineering standards promoted by agencies linked to the Illinois Department of Transportation and federal highway policy discussions in the United States Congress.

Future and planned improvements

Future plans emphasize completing corridor continuity, improving safety at high-crash locations, and enhancing connections to regional freight routes such as the Chicago–Kansas City Expressway and the Interstate 72 corridor. Proposed projects include additional two-lane to four-lane conversions near growth centers, construction of bypasses to reduce through-traffic in town centers like Camp Point, Illinois and Bowen, Illinois, and interchange upgrades to better integrate with U.S. Route 24 and U.S. Route 67. Economic development advocates from organizations associated with the Great River Economic Corridor and chambers of commerce in Quincy, Illinois and Macomb, Illinois have lobbied for federal discretionary grants and state capital appropriations to advance these improvements. Environmental reviews reference nearby resources such as the Mississippi River riparian habitats and regional conservation interests coordinated with agencies related to the Illinois Environmental Protection Agency and federal permitting bodies involved in infrastructure projects.

Major intersections

The corridor connects with several principal routes and nodes that support regional mobility and freight movement. Key intersections include junctions with U.S. Route 24 near the Quincy area, connections to U.S. Route 67 serving north–south flows along the western Illinois corridor, and links to state routes and county highways that feed local traffic from communities like Camp Point, Illinois and Bowen, Illinois. Interchanges and at-grade junctions along the corridor are designed to serve traffic bound for economic centers such as Quincy Medical Group facilities, manufacturing sites tied to the St. Louis and Chicago supply chains, and agricultural processors that rely on access to the Mississippi River and regional rail terminals.

Auxiliary routes and designations

The corridor includes auxiliary alignments, temporary routings, and frontage roads created during phased construction to maintain local access and support detours. Local authorities in Adams County, Illinois, Hancock County, Illinois, Warren County, Illinois, and Henderson County, Illinois coordinate maintenance responsibilities for connectors that link the corridor to municipal streets in towns such as Bowen, Illinois and Camp Point, Illinois. Designation updates have been influenced by statewide route numbering practices and intergovernmental agreements involving entities like the Illinois Department of Transportation and county highway departments, aiming to create coherent signage and traveler information consistent with regional corridors including the Chicago–Kansas City Expressway and interstate networks.

Category:State highways in Illinois