AARoads:United States/Michigan/List of unsigned state trunkline highways

This information comes from [1] (June 29, 2007):

• Old I-69, I-69 BL northeast of Lansing to west of Morrice
• Old I-96 BL, Farmington: 10 Mile Road to M-5 southeast of downtown
• Old I-96 BS, Detroit: I-96 (exit 185) to Cass Avenue
• Old US 12, county line east of Niles to US 12/M-50
• Old US 27, I-69/M-79 in Charlotte to I-496 in Lansing
• Old US 27, I-96 BL in Lansing to US 127 BR south of St. Johns
• Old US 27, US 127 north of St. Johns to dead end
• Old US 31, US 31 BR north of Niles to US 31 north of Berrien Springs
• Old US 31, M-20 north of New Era to Shelby south limits and Shelby north limits to Hart north limits; also US 31 BR to Old US 31 in Hart (West Polk Road, State Street to Oceana Drive)
• Old US 31 BR, Holland: at the US 31 interchange south of downtown
• Old US 127, M-50 to dead end southeast of Jackson
• Old US 127, Lansing: one-way frontage roads of US 127
• Old US 131, county line south of Morley to M-20 in Big Rapids and US 131 BR north of Big Rapids to Reed City south limits
• Old US 131, US 131 BR north of Cadillac to M-42 in Manton
• Old US 131 BR, Grand Rapids: Weston Street between Division Avenue and Ionia Avenue
• Old US 223, Ohio to US 223 southeast of Blissfield
• Old M-14, county line west of Plymouth to Detroit west limit
• Old M-20, US 131 west of Stanwood to 200th Avenue
• Old M-21, I-196 BL in Zeeland to Grandville west limit
• Old M-21, Wyoming: west limit to I-196 BS
• Old M-21, Cascade Road to M-37 east of Grand Rapids
• Old M-24, Caro: M-81 to M-24
• Old M-38, Ontonagon
• Old M-42 (not in the data, [2] says it's new as of June 2007)
• Old M-45, Grand Valley
• Old M-45, Grand Rapids: I-196 to east end of Grand River bridge
• Old M-55, Cadillac: M-115 to US 131 BR and east limits to US 131
• Old M-55, M-55 at Backus to I-75/M-55 west of West Branch
• Old M-59, Rochester Hills: west limit to east limit
• Old M-64, Ontonagon: doesn't include the old bridge
• Old M-84, north from Kloha Road south of Frankenlust
• Old M-99, Beck Road/Beck Street in and between Hillsdale and Jonesville
• Old M-106, Jackson: M-50 to M-106
• Old M-143, East Lansing: west limit to M-43
• Old M-153, Detroit: Wyoming Avenue to US 12
• Old M-154, Harsens Island: end state maintenance to ferry turnoff
• Old M-155, High Hillcrest Drive to I-96 BL in Howell

• ?, Saginaw: M-58 to I-675 (not Connector 58)

[3] is a list of connectors.