Interstate 72 (I-72): Illinois Route, Length, Crashes and Bridges

How long is I-72?

The FHWA Route Log puts I-72 at 179.31 miles, with 177.25 in Illinois and 2.06 in Missouri. Wikipedia and Interstate Guide both list 179.29 miles. They match the Route Log on Illinois and give Missouri 2.04 miles, so the two totals differ by two hundredths of a mile, all on the Missouri side.

In Springfield, I-72 and US 36 ride on I-55 between I-72 exits 97 and 103, roughly six miles going by the exit numbers. Neither route's Route Log row has an overlap note for that stretch. I-72's Illinois figure already equals the end-to-end length the other sources give, so the shared miles appear to be counted in the I-72 row. The crash rates below use the 177.25 Illinois miles exactly as the Route Log lists them.

Where I-72 starts and ends

The west end is exit 157 in Hannibal, Missouri, where I-72 meets US 61, the Avenue of the Saints, at McMasters Avenue. According to Wikipedia, that exit number was picked with a possible future western end at I-35 in Cameron in mind. Heading east, the road crosses the Mississippi into Illinois and runs through Pike County past Hull, Pittsfield and Griggsville. It crosses the Illinois River near Valley City and passes Jacksonville before reaching Springfield. A sign near milemarker 78 marks 90 degrees west longitude.

East of Springfield the road goes by Illiopolis and Niantic to Decatur, then Monticello and Mahomet. The freeway ends at its cloverleaf with I-57 in Champaign. From there the road continues as a one-way pair, Church Street westbound and University Avenue eastbound, for about three more miles into downtown Champaign.

Interstate junctions along I-72

Two other Interstates meet I-72, and the table lists them starting from the Champaign end. I-57 comes first, at the cloverleaf where I-72 ends. I-74 is close by but never meets I-72; Interstate Guide puts it 2.21 miles northeast of the interchange along I-57. I-55 is the other entry. I-72 joins it in Springfield and splits off again at a cloverleaf at I-55 exit 98. Near the Missouri line, I-172 branches north toward Quincy at exit 4 by Fall Creek. It is an I-72 spur, so it is in the auxiliary routes section rather than this list.

Fatal crashes on I-72

From 2020 to 2024, fatal crashes on I-72 killed 16 people in 12 crashes, about 3 deaths a year. Over 179.31 route miles that comes to 1.8 deaths per 100 miles per year, compared with the Interstate average of 9.5. I-72 ranks 56th of the 56 ranked routes, counting from the highest rate, which makes it the lowest on the list.

Every death was in Illinois, where the rate is also 1.8. Missouri's 2.06 miles had no deaths and are too short for a state rate. Sangamon County, around Springfield, and Pike County, at the western end, had 4 deaths each. Macon County, which includes Decatur, had 3, Champaign County had 2 and Piatt County had 1. With counts this small, a single crash moves the yearly figure: 4 deaths in 2020, 3 in each of 2021 and 2022, 5 in 2023 and 1 in 2024. FARS files each crash under the route named on its record, so a crash on the miles shared with I-55 may be counted as an I-55 crash even though the rate gives those miles to I-72.

Counties with the most I-72 crash deaths

Bridges on I-72

The 2025 National Bridge Inventory lists 140 bridges on the I-72 main line, 134 in Illinois and 6 in Missouri. Nine of them, 6.4 percent, are rated Poor. Illinois has 8 of those, or 6.0 percent of its I-72 bridges, and Missouri has 1. Another 108 bridges rate Fair and 23 rate Good. The median I-72 bridge dates from 1976, the year Interstate Guide gives for finishing the road from Springfield to Champaign.

The Mark Twain Memorial Bridge carries I-72 and US 36 over the Mississippi at Hannibal. Interstate Guide describes it as a steel truss bridge 4,491 feet long with a 640-foot main span, dedicated on September 16, 2000, at an estimated cost of $51.45 million, and carrying about 11,000 vehicles a day. Near Valley City, around mile 42, the road crosses the Illinois River on the Valley City Eagle Bridges, two separate two-lane spans.

Tolls on I-72

I-72 does not appear in the list of toll roads, bridges and tunnels that FHWA compiled as of January 1, 2023. Neither Wikipedia nor Interstate Guide mentions priced lanes added since then, so a trip from Hannibal to Champaign, Mississippi crossing included, involves no tolls.

I-72 auxiliary routes

I-72 has one three-digit spur. I-172 leaves I-72 at exit 4 near Fall Creek and heads north to Quincy, signed with IL 110 for its whole length. The Route Log gives it 19.69 miles. It ends at US 24 about 2.5 miles west of Fowler, and the road carries on from there as IL 336 toward Macomb.

How I-72 grew from Champaign to the Mississippi

Wikipedia dates the first construction of I-72 to 1971, and Interstate Guide says the first piece ran west from Champaign to Monticello. The rest of the road to Springfield was complete by November 1976. Until the 1990s, I-72 stopped at I-55 in Springfield.

West of Springfield, Illinois built the Central Illinois Expressway, which had been planned since the early 1960s, and opened it from I-55 to Hull on November 22, 1991. The state proposed calling it I-172, and AASHTO's route numbering committee approved that on June 9, 1991, pending FHWA approval. FHWA wanted I-72 extended instead. AASHTO approved the change on April 22, 1995, giving the expressway the I-72 number and moving I-172 to the IL 336 spur toward Quincy, and I-72 signs went up within about a week of April 27. In September 2000, I-72 moved onto the new Mark Twain Memorial Bridge into Hannibal.

The Illinois General Assembly named all of I-72 the Purple Heart Memorial Highway in 2006, and the stretch from Springfield to Decatur is also the Penny Severns Memorial Expressway. Missouri has tried to take the number farther west. After US 36 was four-laned from Hannibal to Macon, with the last section finished on August 16, 2010, MoDOT asked to extend I-72 west to US 24. FHWA refused in February 2017, saying an Interstate has to end at another Interstate. Interstate Guide says a Hannibal Expressway bypass, estimated at $38 million in a 2007 study, could lead FHWA to approve an extension if it is built, but it has no funding. In May 2023, Missouri lawmakers approved a $2.5 million study of converting US 36 to I-72, and Governor Mike Parson vetoed it in July 2023.

I-72 traffic and road conditions

For a crash or lane closure on I-72 right now, check the two state traveler sites below. Illinois holds all but 2.06 miles of the route, so its site covers nearly the whole trip, and MoDOT's map covers the Hannibal end.

I-72 questions