Illinois State Route 15 runs east-west across St. Clair County. At Belleville, this highway becomes a multi-lane divided highway. Most of it is a expressway, with the exception of a few driveways and a stoplight near Belleville. IL St Rt 15 passes through the following towns in St. Clair County. St. Libory
Fayetteville
Freeburg
Belleville
Cahokia Heights (former Village of Alorton, Village of Cahokia, Village of Centreville; prior to May, 2021)
East St. Louis
IL St Rt 15 is multi-plexed in St. Clair County. Illinois State Route 4, from near St. Libory to Fayetteville.
EB IL St Rt 15 in St. Libory. EB IL St Rt 15 east of IL St Rt 4. EB IL St Rt 15 east IL St Rt 4. SB IL St Rt 4/EB IL St Rt 15 at St. Libory. A junction marker on SB IL St Rt 4/EB IL St Rt 15 near St. Libory. SB IL St Rt 4/EB IL St Rt 15 north of St. Libory. SB IL St Rt 4/EB IL St Rt 15 near St. Libory. SB IL St Rt 4/EB IL St Rt 15 east of Fayetteville. SB IL St Rt 4/EB IL St Rt 15 near the Kaskaskia River in Fayetteville. EB IL St Rt 15 west of north IL St Rt 4. EB IL St Rt 15 west of Fayetteville. EB IL St Rt 15 east of Freeburg. EB IL St Rt 15 east of east IL St Rt 13. A junction marker on EB IL St Rt 13/15. A junction marker on EB IL St Rt 13/15. WB IL St Rt 13/15 near Apple Street in Freeburg. WB IL St Rt 13/15 near White Street in Freeburg. EB IL St Rt 13/15 at North Main Street in Freeburg. WB IL St Rt 13/15 near Jefferson Road. WB IL St Rt 13/15 near Greenmont Road. EB IL St Rt 13/15 west of Greenmont Rd. WB IL St Rt 13/15 east of Belleville. WB IL St Rt 13/15 west of Greenmont Road. EB IL St Rt 15 near IL St Rt 13. WB IL St Rt 15 west of the split with IL St Rt 13. A St. Clair County mile marker. WB IL St Rt 15 at IL St Rt 159. WB IL St Rt 15 at IL St Rt 159. (August, 2022) A BGS on SB IL St Rt 159. EB IL St Rt 15 at IL St Rt 159. EB IL St Rt 15 at IL St Rt 158. A guide marker on WB IL St Rt 158. WB IL St Rt 15 at 11th in Belleville. EB IL St Rt 15 at 11th in Belleville. A guide marker on Belleville West Parkway. WB IL St Rt 15 near Belleville West. WB IL St Rt 15 near IL St Rt 13 on the westside of Belleville. EB IL St Rt 15 at Frank Scott Parkway. WB IL St Rt 15 east of IL St Rt 13 on the westside of Belleville. A BGS on WB IL St Rt 13. A set of BGS's on EB IL St Rt 15. A A set of BGS's on EB IL St Rt 15. EB IL St Rt 15 at IL St Rt 13 on the westside of Belleville. WB IL St Rt 15 near the Shrine in Belleville. WB IL St Rt 15 near the shrine in Belleville. A BGS at the shrine. A BGS at the shrine. WB IL St Rt 15 at IL St Rt 157. A junction marker on SB IL St Rt 157. A BGS on NB IL St Rt 157. A BGS on SB IL St Rt 157. A BGS on NB I-255/EB U.S. Rt. 50. A BGS on NB I-255/U.S. Rt. 50. A BGS on SB I-255/WB U.S. Rt. 50. A BGS on SB I-255/WB U.S. Rt. 50. A BGS on SB I-255/WB U.S. Rt. 50. A BGS on SB I-255/WB U.S. Rt. 50. A BGS on SB I-255/WB U.S. Rt. 50. A BGS on SB I-255/WB U.S. Rt. 50. A BGS on SB I-255/WB U.S. Rt. 50. A BGS on SB I-255/WB U.S. Rt. 50. WB IL St Rt 15 in East St. Louis. The western begin point of IL St Rt 15 in East St. Louis. The western end of IL St Rt 15. The western end marker. The western end of IL St Rt 15. (June, 2022) The western end marker for IL St Rt 15. (June, 2022) IL 13/15 re-built Freeburg-to-Belleville WB IL 13/15 on the northside of Freeburg. (September, 2007) WB IL St Rt 13/15 at the eastern end of the work zone. (August, 2006) WB IL St Rt 13/15 at the point above. (April, 2007) WB IL St Rt 13/15 at the point above. (September, 2007) The new EB lanes will be to the left of the current lanes. (August, 2006) Traffic is using what will be the EB lanes when the old road is re-built to be the WB lanes. (July, 2008) EB IL St Rt 13/15 at the same point as the photo above. (July, 2009) At the top of the hill in the photo above the road-way will shift. WB lanes will be to the right of the current lanes. (August, 2006) The new WB lanes are to the right. (April, 2007) WB IL St Rt 13/15 at the point above. (September, 2007) EB IL St Rt 13/15 on the hill north of Freeburg. Traffic is going from the old two lane road to the new EB lanes. (July, 2008) WB IL St Rt 13/15 in the work zone. The new WB Lanes are to the right. (April, 2007) WB IL St Rt 13/15 near the eastside of the sharp curve. This is being streched out. (August, 2006) WB IL St Rt 13/15 at the curve. (April, 2007) WB IL St Rt 13/15 at the point above. (September, 2007) WB IL St Rt 13/15 in the middle of the curve. (August, 2006) WB IL St Rt 13/15 at the point above. (September, 2007) EB IL St Rt 13/15 in the middle of the curve. (July, 2008) EB IL St Rt 13/15 in the middle of the curve. Same point as the picture above. (July, 2009) EB IL St Rt 13/15 in the curve east of Greenmont Road. (July, 2008) EB IL St Rt 13/15 at the curve east of Greenmount Road. (July, 2009) WB IL St Rt 13/15 near the western end of the work zone. (April, 2007) WB IL St Rt 13/15 at the west end of the work zone. (September, 2007) EB IL St Rt 13/15 at the same point as the photo above. (July, 2008) EB IL St Rt 13/15 at the same point as the photo above. (July, 2009) EB IL 13/15 near Greenmont Road. (July, 2008)
