U.S. Federal Route 421 is a north-south highway in Marion and Hamilton Counties. This highway briefly passes through Hamilton County twice. Once between Boone and Marion County. Then again on the Interstate 465 loop near mile-post 31. Like the other numbered surface highways at Indianapolis, U.S. Rt. 421 by-passes the city on the Interstate 465 loop. This highway runs along the north and eastsides from Michigan Road to Interstate 74 on the southeast side of the city. U.S. Rt. 421 passes through the following town in Marion-Hamilton Counties. Indianapolis U.S. Rt. 421 is multi-plexed in Marion-Hamilton Counties. Interstate 465, at Indianapolis.
A BGS on EB I-465/U.S. Rt. 52. A BGS on EB I-465/U.S. Rt. 52. BGS on WB I-465/U.S. Rt. 52; NB U.S. Rt. 421. NB I-465/U.S. Rt. 31-421; WB U.S. Rt. 421 in Northern Marion County. EB I-465/U.S. Rt. 52; SB U.S. Rt. 421 near Township Line Road. EB I-465/U.S. Rt. 52; SB U.S. Rt. 421 at the Hamilton/Marion County Line. EB I-465/U.S. Rt. 52; SB U.S. Rt. 421 west of U.S. Rt. 31. EB I-465/U.S. Rt. 52; SB U.S. Rt. 31/421 east of U.S. Rt. 31. EB I-465/U.S. Rt. 52; SB U.S. Rt. 31/421 at the Hamilton/Marion County Line. SB I-465; SB U.S. Rt. 31/421; EB U.S. Rt. 52 north of Allisonville Road. SB I-465; U.S. Rt. 31/421, EB U.S. Rt. 52 two miles from I-69. (October, 2017) SB I-465; U.S. Rt. 31/421, EB U.S. Rt. 52 over one mile from I-69. (October, 2017) SB I-465; SB U.S. Rt. 31/421; EB U.S. Rt. 52 at Allisonville Road. SB I-465; U.S. Rt. 31/421, EB U.S. Rt. 52 under one mile from I-69. (October, 2017) SB I-465; U.S. Rt. 31/421, EB U.S. Rt. 52 near I-69. (October, 2017) SB I-465; U.S. Rt. 31/421, EB U.S. Rt. 52 at I-69. (October, 2017) SB I-465; SB U.S. Rt. 31/421; SB IN St Rt 37; EB U.S. Rt. 52 south of I-69. SB I-465; U.S. 31/421; IN St Rt 37/67, EB U.S. Rt. 52 two miles from I-70. (October, 2017) SB I-465; U.S. 31/421; IN St Rt 37/67, EB U.S. Rt. 52, WB U.S. Rt. 36/40 one mile from I-70. (October, 2017) SB I-465; U.S. 31/421; IN St Rt 37/67, EB U.S. Rt. 52, WB U.S. Rt. 36/40 near I-70. (October, 2017) SB I-465; U.S. 31/421; IN St Rt 37/67, EB U.S. Rt. 52, WB U.S. Rt. 36/40 at I-70. (October, 2017) SB I-465; SB U.S. Rt. 31/421; SB IN St Rt 37/67; WB U.S. Rt. 36 north of U.S. Rt. 40. SB I-465; U.S. 31/421; IN St Rt 37/67, EB U.S. Rt. 52, WB U.S. Rt. 36/40 two miles from I-74. (October, 2017) SB I-465; U.S. 31/421; IN St Rt 37/67, EB U.S. Rt. 52, WB U.S. Rt. 36/40 one mile from I-74. (October, 2017) SB I-465; U.S. 31/421; IN St Rt 37/67, WB U.S. Rt. 36/40 under one mile from I-74. (October, 2017) SB I-465; U.S. 31/421; IN St Rt 37/67, WB U.S. Rt. 36/40 near I-74. (October, 2017) SB I-465; U.S. 31/421; IN St Rt 37/67, WB U.S. Rt. 36/40 at I-74. (October, 2017) EB I-74/SB U.S. Rt. 421 east of I-465. WB I-74/NB U.S. Rt. 421 at I-465. (July, 2019) WB I-74/NB U.S. Rt. 421 before I-465. (July, 2019) WB I-74/NB U.S. Rt. 421 near I-465. (July, 2019) A BGS on WB I-74/NB U.S. Rt. 421. WB I-74/NB U.S. Rt. 421 a half mile from I-465. (July, 2019) WB I-74/NB U.S. Rt. 421 one mile from I-465. (July, 2019) WB I-74/NB U.S. Rt. 421 west of Post Road. A junction marker on NB Post Road. A BGS on Post Road. A BGS on Post Road. EB I-74/SB U.S. Rt. 421 east of Post Road. EB I-74/SB U.S. Rt. 421 east of Post Road. WB I-74/NB U.S. Rt. 421 west of Action Road. EB I-74/SB U.S Rt. 421 at London Road. EB I-74/SB U.S. Rt. 421 east of London Road.
