Interstate 840 (Tennessee)

The route that is now Interstate 840 had its origins in the 1975 Tennessee Highway System Plan issued by TDOT for the next four years, which first identified the need for an outer beltway around Nashville by 1995.[7] The I-840 project was initiated in 1986 with the passage of the Better Roads Program by the Tennessee General Assembly.[8] This program, which had been proposed and spearheaded by then-governor Lamar Alexander, increased the state's gasoline and diesel taxes to fund six new freeway projects and a backlog of 15 projects that had been labeled as top priorities, as well as other projects.[9] I-840 was the largest of these six freeway projects, dubbed "Bicentennial Parkways", and was initially expected to cost $351 million (equivalent to $708 million in 2019[10]).[8] While initially referred to as I-840 in the state plan,[8] the highway was constructed entirely with state transportation funds and was officially designated as a state route.[11] The 1986–1987 state budget contained the initial funding for the project.[3] Planning work began in 1988, and the alignment for the first section was announced in December of that year.[3] Survey and design work began in 1989,[12] and the alignment for the remainder of the route was announced in January 1990.[3] Planners considered using SR 396, a short controlled-access connector between US 31 and I-65 in Spring Hill, for part of I-840, but ultimately chose a location about 6 miles (9.7 km) to the north.[13] The first contract for construction was awarded on August 2, 1991,[14] and work progressed in stages.[3]

The first section of I-840, located between I-40 in Lebanon and Stewart's Ferry Pike, opened on August 2, 1995.[15] The segment between Stewart's Ferry Pike and I-24 near Murfreesboro was completed on November 21, 1996.[16][17] On November 30, 2000, the section between I-24 and US 31A/US 41A near Triune was opened.[18][19] The portion between US 31A/US 41A and US 431 (Lewisburg Pike) near Franklin, including the interchange with I-65, opened on October 18, 2001.[20][21] The section between I-40 near Dickson and SR 100 opened on December 5, 2002.[22][23] Due to high costs and environmental concerns, the proposed northern half of I-840 was indefinitely placed on hold in 2003.[3] The short segment between US 431 and US 31 (Columbia Pike) opened to traffic on September 9, 2005.[24][25]

Construction of the majority of I-840 was met with very little controversy.[11] As work moved into predominantly rural southwestern Williamson County, however, a group of landowners opposed to the route began a movement to stop its construction in 1997.[26][27] Between the late 1990s and mid-2000s, these landowners, spearheaded by singer-songwriter Gene Cotton, filed complaints and eventually lawsuits in an effort to have TDOT address both environmental and aesthetic issues, considerably slowing work on the segment between SR 100 and US 31.[11] A number of criticisms were also made about TDOT's handling of the construction of the route, such as an accusation that they chose to construct I-840 as a state route to avoid federally required environmental studies.[26] TDOT awarded the first contract for the segment between SR 100 and SR 46 on June 14, 2002,[28] but additional litigation forced TDOT to completely cease work on this segment three months later.[29] As a result of these lawsuits, TDOT chose to slightly modify the design and employ new construction methods on the remaining sections the following year.[3] These changes included construction of bridges over streams feeding the South Harpeth River instead of culverts; multiple wildlife underpasses; and designation of the remaining sections as a scenic highway, which prohibits billboards and uses brown powder-coated guardrail.[11][3] As part of the redesign, TDOT formed a citizen's resource team, made up of nine local residents who worked with TDOT to select the final designs and alignment of these stretches.[30] A proposed interchange at Leiper's Creek Road was also canceled.[31]

On February 9, 2006, TDOT announced that the realignment of the final segment of I-840 had been chosen and that work on the unfinished sections would proceed.[32] The first contract for construction of the segment between SR 100 and SR 46 was re-awarded on June 1, 2007,[33] and construction on I-840 resumed the following month.[34] This segment opened on October 27, 2010.[35] The contract for the segment between Leiper's Creek Road and US 31 was awarded on December 12, 2008,[36] and on February 19, 2010, TDOT awarded the final construction contract for I-840, the segment between SR 46 and Leiper's Creek Road.[37] These two segments, the final 14.2 miles (22.9 km) of I-840, were opened on November 2, 2012.[3] The project took 26 years to complete and cost $753.4 million (equivalent to $846 million in 2019[10]).[11]

Map showing the complete section of I-840 and the approximate location of the formerly proposed northern segment.

TDOT was first authorized to begin studies for a northern loop of I-840 north of Nashville and past Dickson, Clarksville, Springfield, and Gallatin by the state legislature in 1993.[1] Environmental studies began in 1994 and a draft environmental impact statement (DEIS) was released in 1995.[7] On July 12, 1996, TDOT announced their first proposal for the northern section's alignment.[38][39] Many residents in the predominantly rural and agricultural areas where the route was to pass were initially opposed.[7] Plans were later abandoned and the General Assembly ordered TDOT to discontinue further studies and planning of that highway because of state budget problems. An entire circular loop would possibly be about 187 miles (301 km) long, with the northern segment ranging from 86 to 116 miles (138 to 187 km).[7] Other important objections against additional extensions of I-840 include the hilly nature of the terrain north of Nashville (the Highland Rim), which would require huge and costly amounts of excavation, soil relocation, and bridge construction.[1] On October 31, 2003, TDOT placed the northern loop plan on indefinite hold, citing a lack of documented transportation needs and lack of participation from local politicians.[1] The western terminus of I-840 actually contains a very short unused extension, constructed in anticipation of the northern segment.[5]

TDOT first submitted a request to the FHWA to redesignate SR 840 as I-840 in November 1991. This was withdrawn two months later after it was chosen to construct the entire route with state funds.[40]

In 2015, TDOT submitted a request to AASHTO to redesignate SR 840 as I-840. Though the application had an error that required TDOT to refile it, AASHTO conditionally approved it and submitted it to the FHWA for their approval.[41][42] FHWA approved the change on July 22, 2015, and AASHTO finalized their approval on September 25, 2015.[43] TDOT announced on August 12, 2016, that it would start replacing the signs to change over the designation the week of August 14, and that the project would be completed by the end of the year at a cost of $230,000 (equivalent to $240,000 in 2019[10]).[2]

In 2005, the Tennessee General Assembly passed legislation designating I-840 as the "Tennessee National Guard Parkway".[44] Since 2007, the state has named bridges on I-840 in honor of members of the Tennessee National Guard killed in the global War on Terror.[45]