This highway crosses four interstate highways on its journey through the state and actually crosses Interstate 240 twice within the City of Memphis but interchanges with it only at Union Avenue. US 51 is the westernmost south–north United States Highway in the State of Tennessee. US 51 is an interstate standard facility[1] from Dyersburg to South of Troy and then resuming interstate standard status north of Union City to South Fulton. US 51 is a four-lane or larger facility throughout the state with some sections north of Dyersburg carrying a 70 mph (110 km/h) speed limit.
Near Henning is also the site of the Hatchie River Bridge collapse on April 1, 1989 that killed 8 motorists when 3 spans of the structure collapsed. The 54-year-old bridge was 45 miles (72 km) north of Memphis and carried the northbound lanes of US 51. Its collapse was the result of pier scour and movement of the river channel.[3][4]
US 51 carries the Tennessee Scenic Parkway designation from its junction with SR 385 in Millington to SR 104 in Dyersburg and also carries the Great River Road designation from US 64/US 70/US 79 in Memphis to SR 88 in Halls.[1]
Most of US 51 north of Dyersburg is expected to be converted to Interstate standards as part of future I-69. Plans currently call for I-69 to run along the existing US 51 freeway from Dyersburg to Troy and from Union City to South Fulton. This section is part of SIU 7 for I-69 and will require few changes beyond resigning the existing highway, however, a bypass route around Troy and Union City will need to be built before this section of future I-69 is completed.[5][6] The Union City Bypass was opened in November 2023 under the temporary designation of SR 690, but there is currently no timeline for when the Troy bypass will be built.[7][8]
Northern end of US 45W and unsigned SR 3 overlap; southern end of unsigned SR 215 overlap; US 45W and US 45E merge to form US 45; southern end of freeway; interchange
The highway begins as South Main Avenue at a large three-way intersection with US 51/SR 3 on the southern edge of the city. It heads north, concurrent with SR 211, as a two-lane road through a business district before traveling through wooded areas and crossing a bridge over the North Fork of the Forked Deer River into downtown. US 51 Bus./SR 211 pass by the Dyer County Courthouse and becomes concurrent with SR 104 (East Court Street) as the road becomes North Main Avenue shortly before making an abrupt left turn onto McGaughey Street. US 51 Bus./SR 211 then split before heading through neighborhoods along Troy Avenue before turning right onto Gordon Street. The highway then makes a left turn onto North Sampson Avenue and passes through more neighborhoods before merging onto St. John Avenue. They then travel through a business district before widening to a four-lane highway and coming to an end at an intersection with US 51/SR 3, where US 51 Bus. ends and SR 211 follows northbound US 51/SR 3 north on St. John Avenue.
US 51 at the Mississippi state line
Future I-69 / US 51 / Purchase Parkway at the Kentucky state line
