A change proposed in the 1960s and implemented in the 1970s shifted the southern end of US 223 to replace M-151 and then run along the US 23 freeway between Whiteford Township, Michigan, and Sylvania, Ohio.

Congress has designated this corridor as part of Interstate 73 (I-73), although neither state intends to complete the freeway at this time.

US 223 meets its former routing and turns northwesterly along Lansing Road,[4][5] crossing a branch of the Indiana & Ohio Railway.

[4][5] US 223 returns to a due west track as it crosses a branch of the Norfolk Southern Railway, and the roadway approaches the outskirts of Adrian.

US 223 crosses Beaver Creek and then intersects M-34 on the western city line in a residential section of Adrian.

As US 223 crosses fully into the city of Adrian, it continues northwesterly, then turns due west at the intersection where it meets its business loop's western terminus.

[4][5] US 223 passes out of flat farmlands into the Irish Hills region as the highway runs northeast of Manitou Beach as the roadway rounds the northern shore of Devils Lake.

[9] As early as 1912, the Ohio section of what is now US 223 was shown on maps as SR 54, however the road was not signed with the number at the time.

[14] In 1930, US 127 south of Somerset was rerouted to replace M-14 to the state line and extended to end in Cincinnati, Ohio.

This change would have rerouted the highway to replace M-151 in southern Monroe County, and use the US 23 freeway to connect to Sylvania, Ohio.

[25] The Michigan State Highway Department truncated M-151 in 1965, eliminating the section that ran eastward through Samaria to US 25 south of Monroe.

[21] The last major change occurred when the Ohio Department of Transportation (ODOT) truncated US 223 at exit 234.

[29][30] A local regional planning group in Michigan proposed upgrading the section of US 223 through Lenawee County in 1990, citing increased congestion and accidents in the previous five years.

[31] Subsequent upgrades during 2000 added passing lanes near Palmyra and 6.6 miles (10.6 km) of roads were resurfaced.

[4] While there are no immediate plans to convert the section of US 127 between St. Johns and Ithaca to freeway, the Michigan Department of Transportation (MDOT) continues to purchase parcels for right-of-way to be used for future upgrades.

[36] MDOT abandoned further study of I-73 after June 12, 2001, diverting remaining funding to safety improvement projects along the corridor.

[38] According to press reports in 2011, a group advocating on behalf of the freeway is working to revive the I-73 project in Michigan.

"[39] The Lenawee County Road Commission is not interested in the freeway, and according to the president of the Adrian Area Chamber of Commerce, "there seems to be little chance of having an I-73 link between Toledo and Jackson built in the foreseeable future.

The route follows Maumee Street to its northern terminus, meeting US 223 again northwest of downtown Adrian.