U.S. Federal Route 40 is a east-west highway across Central St. Charles County. This runs along a expressway corridor through the entire county. From the Missouri River to near Dardenne Prairie it runs with Interstate 64. Dardenne Prairie to Interstate 70 this is being up-graded to a expressway. U.S. Rt. 40 joins Interstate 70 to the St. Charles/Warren County Line. U.S. Rt. 40 passes thorugh the following towns in St. Charles County. Weldon Springs
St. Peters Dardenne Prairie
O'fallon
Lake St. Louis
Wentzville
U.S. Rt. 40 is multi-plexed in St. Charles County. Interstate 64, from the St. Louis/St. Charles County Line to near Darenne Park. U.S. Rt. 61, from the St. Louis/St. Charles County Line to Wentzville.
Interstate 70, from Wentzville to the St. Charles/Warren County Line.
EB I-64/U.S. Rt. 40; SB U.S. Rt. 61 crossing the Missouri River. EB I-64/U.S. Rt. 40; SB U.S. Rt. 61 at the Missouri River. EB I-64/U.S. Rt. 40; SB U.S. Rt. 61 east of Research Park Circle. EB I-64/U.S. Rt. 40; SB U.S. Rt. 61 east of MO St Rt 94. A junction marker on WB MO St Rt 94. A BGS on WB MO St Rt 94. WB I-64/U.S. Rt. 40; NB U.S. Rt. 61 in Weldon Springs. WB I-64/U.S. Rt. 40; NB U.S. Rt. 61 near MO Sec St Rt N. EB I-64/U.S. Rt. 40; SB U.S. Rt. 61 at MO St Rt 364/MO Sec St Rt N. A BGS on EB MO St Rt 364. EB I-64/U.S. Rt. 40; SB U.S. Rt. 61 west of MO St Rt 364/MO St Rt N. WB U.S. Rt. 40; NB U.S. Rt. 61 near Lake St. Louis. WB U.S. Rt. 40; NB U.S. Rt. 61 in Lake St. Louis. Several interchanges have been built along U.S. Rt. 40/61, but the expressway has not been complete. Thus the roadway shifts several times. (July, 2004) Same point as the picture above. (July, 2009) WB U.S. Rt. 40/NB U.S. Rt. 61 near Prospect Road. WB I-64/U.S. Rt. 40; NB U.S. Rt. 61 near Prospect Road. EB I-64/U.S. Rt. 40; SB U.S. Rt. 61 east of Prospect Road. WB U.S. Rt. 40/NB U.S. Rt. 61 at one of the last overpasses being built. (July, 2009) WB I-64/U.S. Rt. 40; NB U.S. Rt. 61 one mile from I-70. (September, 2010) WB U.S. Rt. 40/NB U.S. Rt. 61 south of I-70. WB U.S. Rt. 40/NB U.S. Rt. 61 at EB I-70. (July, 2004) The same point as the photo above. (July, 2009) A BGS on WB I-70. A BGS on WB I-70. A BGS on EB I-70/U.S. Rt. 40. EB I-70/US. Rt. 40 in Wentzville. A set of guide BGS's in Wentzville.