TN 840 from I-40 to I-24 1996 Official

TN 840 extended to US 31A-41A 2001 Official

In 2001, TN 840 was extended west to US 431 Franklin.
In 2002, a second segment was opened from I-40 near Dickson southeast to TN 100.
In 2003, the northern loop around Nashville was put on indefinite hold. An EIS was completed on the northern loop in 1995.
In 2005, TN 840 was extended from US 431 west to US 31.

TN 840 extended to US 431; western segment appears 2004 Official

TN 840 extended to US 31 2006 Official

In 2010, the western piece was extended east to TN 46.
In November 2012, the two segments were connected, completing the souther loop of Nashville.

TN 840 west segment extends to TN 46 2012 Official

TN 840 segments are connected 2013 Official

In 2015, TN 840 was redesignated as I-840.

TN 840 becomes I-840
2017 Official

EXIT 1 - I-40 (exit 176): 0 - 0 EXIT 7 - TN 100: 1.1 - 7.2 EXIT 14 - TN 46: 6.8 - 14.0 EXIT 23 - TN 246: 8.8 - 22.8 EXIT 28 - US 31, TN 6: 5.4 - 28.2 EXIT 30 - US 431, TN 106: 2.1 - 30.3 EXIT 31 - I-65 (exit 59): 0.7 -31.0 EXIT 34 - Peytonsville-Trinity Rd: 3.8 - 34.8 EXIT 37 - Arno Rd: 2.2 - 37.0 EXIT 42 - US 31 ALT, US 41 ALT, TN 11: 4.8 - 41.8 EXIT 47 - TN 102: 1.5 - 46.8

EXIT 50 - Veterans Pkwy: 3.9 - 50.7 EXIT 53 - I-24 (exit 74): 2.3 - 53.0 EXIT 55 - US 41, US 70 ALT, TN 1: 2.0 - 55.0 EXIT 57 - Sulphur Springs Rd: 2.7 - 57.7 EXIT 61 - TN 266: 3.6 - 61.3 EXIT 65 - TN 452: 3.8 - 65.1 EXIT 67 - Couchville Pike: 1.4 - 67.2 EXIT 70 - Stewarts Ferry Pike: 3.3 - 70.5 EXIT 72 - TN 109, TN 265: 1.5 - 72.0 EXIT 76 - I-40 (exit 235): 4.8 - 76.8