U.S. Federal Route 40 runs east-west across Boone County. From the Boone/Callaway County Line to near Midway it runs along Interstate 70. U.S. Rt. 40 passes through the following towns in Boone County. Columbia
Midway U.S. Rt. 40 is multi-plexed in Boone County. Interstate 70, from the Boone/Callaway County to near Midway.
WB I-70/U.S. Rt. 40 east of Columbia. A BGS on SB U.S. Rt. 63. A junction marker on SB U.S. Rt. 63. EB I-70/U.S. Rt. 40 at BUSN Loop I-70, near U.S. Rt. 63. A BGS on NB MO St Rt 763. EB I-70/U.S. Rt. 40 at MO St Rt 163. A set of guide markers on NB MO St Rt 163. WB I-70/U.S. Rt. 40 west of Columbia. A BGS on WB I-70/U.S. Rt. 40. A BGS on EB I-70. WB U.S. Rt. 40/MO St Rt 240 near Rocheport.