Interstate 72 and U.S. 36 at the Mark Twain Bridge to East Hannibal, Illinois. Photo taken by Jeff Royston (02/05/08).
Interstate 72 stretches across central Illinois from Hannibal, Missouri to Champaign-Urbana along a mostly rural route. Prior to 1995, the freeway comprised just an 80-mile route east from Springfield to Decatur and Champaign. The Central Illinois Expressway (U.S. 36) extended the route west to Quincy. This included designating a business loop through Jacksonville.
Illinois 110 and Missouri 110, collectively the Chicago-Kansas City (CKC) Expressway, overlap with Interstate 72 east from U.S. 36 and Hannibal to Interstate 172 north. Designated in 2010, the expressway follows a series of preexisting routes from I-35 / 435 outside Kansas City to the Jane Byrne (Circle) Interchange at I-90 & 94 / I-290 in Chicago, Illinois.
Presently I-72 ends at U.S. 61 (Avenue of the Saints) in Hannibal, but further lengthening is proposed by Marion County. The five-item transportation list finalized by the County Commission on February 16, 2016 added the upgrade of U.S. 36, from the Mark Twain Memorial Bridge across the Mississippi River, to the split of U.S. 24/36 near Rocket Plaza, as a new priority. Citing potential benefits including economic development and marketing of Hannibal Lakeside Industrial Park, the Commission advocated extending Interstate 72 west approximately seven miles.1 The proposed extension was also a topic of discussion at the Missouri Highways and Transportation Commission monthly meeting held in Hannibal on September 1, 2016.2
The Federal Highway Administration (FHWA) denied the Missouri Department of Transportation request to lengthen I-72 west to U.S. 24 in February 2017. FHWA cited rules that Interstates must end at other Interstates, despite I-72 currently ending at U.S. 61. When the Mark Twain Bridge opened in September 2000, U.S. 61 was the best end point option available for Interstate 72. Since the bridge met Interstate standards, FHWA approved the 1.75 mile extension into Missouri.6
U.S. 36 is a controlled access expressway west to Cameron. This corridor is also a part of Missouri 110 (CKC). If the Hannibal Expressway gets built around the west side Hannibal, estimated to cost $38 million per a 2007 study, then FHWA may approve extending Interstate 72.6 The bypass would link with the U.S. 36 and U.S. 24 interchange near Rocket Plaza.
The proposed extension of Interstate 72 through Missouri from Hannibal to St. Joseph is part of High Priority Corridor 61: Missouri Corridors.
Interstate 72 overlaps with U.S. 36 from Hannibal, Missouri east to Decatur, Illinois. U.S. 51 joins the route to bypass Decatur, with I-72 traveling independent of a US highway eastward from Exit 141 to Champaign.
Interstate 72 was completed between Springfield and Champaign in November 1976. Planned since the early 1960s, the Central Illinois Expressway portion of I-72, from Interstate 55 west to Hull, opened to traffic on November 22, 1991.3 Signing of the route as Interstate 72 commenced within a week of April 27, 1995.4
Illinois first proposed the designation of Interstate 172 for the Central Illinois Expressway between Illinois 336 near East Hannibal and I-55 at Springfield. The AASHTO Route Numbering Committee approved the establishment of I-172 on June 9, 1991, with it subject to both Federal Highway Administration (FHWA) approval and completion of the route. The FHWA however preferred to designate this route as an extension of I-72. Due to this change, Interstate 172 was moved to the Illinois 336 freeway spurring north from the proposed I-72 to Quincy and U.S. 24. AASHTO approved both routes on April 22, 1995.
Part of the extension of Interstate 72 included the construction of the Mark Twain Memorial Bridge across the Mississippi River. The steel truss bridge was dedicated on September 16, 2000. The following bridge facts were based on information distributed by the “Hannibal Bridge Dedication Steering Committee”:
- Estimated cost: $51.45 Million.
- Overall length: 4,491 feet; Overall Width: 85 feet and eight inches (including four twelve-foot travel lanes, ten-foot outside shoulders, six-foot inside shoulders, and a concrete traffic barrier in a three-foot wide median).
- The Missouri approach consists of continuous composite prestressed concrete girders: two are 85 feet long, one is 170 feet long, and the second is 105 feet long.
- The Illinois side consists of the same type of girders over wetlands: six are 220 feet long, 12 are 130.5 feet long, one is 151 feet long (steel plate girders), one is 218 feet long (steel plate girders), and one is 145 feet long (steel plate girders).
- The new bridge is located halfway between the existing bridge (old U.S. 36) and the railroad bridge to the north. It is at River Mile 309.6.
- 11,000 vehicles traverse it daily.
- The bridge is designed for seismic forces.
- The main truss span is 89 feet wide and 640 feet long.
Exit numbers in Missouri reflect the distance to the U.S. 36 interchange with Interstate 35 at Cameron, where Missouri 110 (CKC) turns south. There are no plans to extend Interstate 72 west from Hannibal all the way to I-35 or to Interstate 29 at St. Joseph. An $80-million project did upgrade 52 miles of U.S. 36 west from Hannibal. The four lane expansion started in September 2005 with preliminary design work. Spanning four counties, the project was finished in the following order:5
- Hannibal west to Monroe City – August 7, 2009.
- Monroe City west to Shelbina – June 17, 2010.
- Shelbina to Macon – August 16, 2010