U.S. Federal Route 50 runs briefly in the northwestern corner of Monroe County. The entire time this highway is in Monroe County, it is on Interstate 255. U.S. Rt. 50 passes through the following towns in Monroe County. Columbia U.S. Rt. 50 is multi-plexed in Monroe County. Interstate 255, from the St. Clair/Monroe County Line to Illinois/Missouri State Line.
NB I-255/EB U.S. Rt. 50 at the Mississippi River. NB I-255/EB U.S. Rt. 50 at the Mississippi River. SB I-255/WB U.S. Rt. 50 at the Mississippi River. SB I-255/WB U.S. Rt. 50 at the Mississippi River. SB I-255/WB U.S. Rt. 50 at the J.B. Bridge. SB I-255/WB U.S. Rt. 50 crossing the Mississippi River. NB I-255/EB U.S. Rt. 50 at the Illinois State Line. NB I-255/EB U.S. Rt. 50 on the Illinois side of the JB Bridge. NB I-255/EB U.S. Rt. 50 at the Illinois Welcome Sign. (2006) NB I-255/EB U.S. Rt. 50 at the Illinois Welcome Sign. (September, 2007) NB I-255/EB U.S. Rt. 50 at the Illinois Welcome Sign. (June, 2022) NB I-255/EB U.S. Rt. 50 at the Illinois Welcome Sign. (May, 2023) A mileage sign on SB I-255/WB U.S. Rt. 50. SB I-255/WB U.S. Rt. 50 west of IL St Rt 3-Columbia Interchange. NB I-255/EB U.S. Rt. 50 at south IL St Rt 3-Columbia Interhcange. A BGS on NB I-255/EB U.S. Rt. 50. A BGS on NB I-255/EB U.S. Rt. 50. SB I-255/WB U.S. Rt. 50 at the IL St Rt 3-Columbia Interchange. A BGS on NB I-255/U.S. Rt. 50. A BGS on SB I-255/IL St Rt 3; WB U.S. Rt. 50. A set of BGS's on NB IL St Rt 3. A BGS on SB I-255/IL St Rt 3; WB U.S. Rt. 50. A BGS on SB I-255/IL St Rt 3; WB U.S. Rt. 50. SB I-255/IL St Rt 3; WB U.S. Rt. 50 south of the Monroe/St. Clair County Line. SB I-255/IL St Rt 3; WB U.S. Rt. 50 at the Monroe/St. Clair County Line. SB I-255/IL St Rt 3; WB U.S. Rt. 50 at the Monroe/St. Clair County Line.
