|Length||613.41 mi (987.19 km)|
|South end||I-26 in Cayce, SC|
| I-20 in Columbia, SC|
I-85 in Charlotte, NC
I-40 in Statesville, NC
I-74 near Mt. Airy, NC
I-81 between Fort Chiswell and Wytheville, VA
I-64 between Beckley and Charleston, WV
I-79 near Charleston, WV
I-70 in Cambridge, OH
I-76 in Akron, OH
I-80 / Ohio Turnpike in Richfield, OH
|North end||I-90 in Cleveland, OH|
|States||South Carolina, North Carolina, Virginia, West Virginia, Ohio|
Interstate 77 (I-77) is a north–south Interstate Highway in the eastern United States. It traverses diverse terrain, from the mountainous state of West Virginia to the rolling farmlands of North Carolina and Ohio. It largely supplants the old US Route 21 (US 21) between Cleveland, Ohio, and Columbia, South Carolina, as an important north–south corridor through the middle Appalachians. The southern terminus of I-77 is in Cayce, South Carolina in Lexington County at the junction with I-26. The northern terminus is in Cleveland at the junction with I-90. Other major cities that I-77 connects to include Charlotte, North Carolina; Charleston, West Virginia; and Akron, Ohio. The East River Mountain Tunnel, connecting Virginia and West Virginia, is one of only two instances in the United States where a mountain road tunnel crosses a state line. The other is the Cumberland Gap Tunnel, connecting Tennessee and Kentucky. I-77 is a snowbird route to the Southern United States for those traveling from the Great Lakes region.
I-77 begins as an eight-lane highway at I-26 in the far southeastern part of the Columbia metropolitan area. In the Columbia area, I-77 offers access to Fort Jackson before meeting I-20 in the northeastern part of the city. This segment of I-77, combined with I-20 and I-26, form a beltway around Columbia, though it is not officially designated as such.
The final section of the entire length of I-77 was completed in Columbia in 1995.
I-77 through North Carolina begins at the South Carolina state line at Pineville. It narrows to six lanes on the North Carolina side south of Charlotte and then widens to 8 and 10 lanes through downtown before entering the North Carolina Piedmont region. In Charlotte, it intersects I-85 as well as intersecting each of the loops of I-485 and I-277 (twice). North of Charlotte, it skirts Lake Norman where it narrows again to four lanes before passing through Huntersville, Cornelius, Davidson, and Mooresville. At Statesville, 40 miles (64 km) north of I-85, it intersects I-40 and US 70. Next, it crosses over US 421 in Yadkin County and continues on through Elkin. The final intersection in the state is with a discontinuous section of I-74 near Mount Airy.
I-77 in Charlotte is also known as the Bill Lee Freeway; this designation stretches from exit 6 (South Tryon Street/Woodlawn Road) in Charlotte to exit 33 (US 21 north), near Mooresville. A six-mile (9.7 km) portion south of the city is called the General Younts Expressway. When I-77 crosses over I-85 (which runs in an east–west direction through the interchange), the northbound lanes are to the west of the southbound lanes.
North Carolina completed its section of I-77 in 1975.
I-77 through Virginia passes through two tunnels: the Big Walker Mountain Tunnel and the East River Mountain Tunnel. For eight miles (13 km), I-77 and I-81 overlap near Wytheville. This is a wrong-way concurrency, where two roads run concurrent with each other but are designated in opposite directions.
On March 31, 2013, there was a nearly 100-car pileup on I-77 near Fancy Gap; as a result of that crash, electronic variable speed limit signs are now in place along that stretch of I-77. The speed limit can be adjusted according to driving conditions at a given time.
I-77 enters West Virginia through the East River Mountain Tunnel. At milepost 9, I-77 becomes cosigned with the West Virginia Turnpike for the next 88 miles (142 km), a toll road between Princeton and Charleston. It is concurrent with I-64 to Charleston at Beckley. The speed limit is 70 mph (110 km/h) for most of the length, with a 60-mile-per-hour (97 km/h) limit for the section between Marmet and the toll plaza near Pax.
It enters Charleston via the Yeager Bridge before splitting off at a four-level junction with I-64. Two miles (3.2 km) north of the city center, it junctions with I-79, before proceeding north to Ripley and Parkersburg.
North of Charleston, I-77 is known as the Korean War Veterans Memorial Highway.
The interchange with I-70 at Cambridge is (or at least at one time was) thought to be the largest interchange in the world, covering over 300 acres (120 ha).
I-77 continues north through Canton and then Akron, where it connects with I-76. The interchange with I-80, the Ohio Turnpike, between Akron and Cleveland was completed in December 2001; previously, traffic had to exit at State Route 21 (SR 21) to access the Turnpike. I-77 ends at I-90 in Cleveland.
Officially designated to run from Port Huron, Michigan, to Charlotte, North Carolina, I-77 appeared on the original Interstate System route numbering plan in 1957. The part of I-94 from Detroit, Michigan, northeast to Port Huron was originally planned as I-77 in 1957; the current I-77 was I-79. When the current I-79 was added in Pennsylvania, the I-77 designation was moved to its current route, but the I-77 in Michigan also remained in the 1958 numbering plan. It soon became part of I-94.
Originally, I-77 was to terminate at I-85 in Charlotte. However, Congress, in its 1969 amendments to the Federal-Aid Highway Act of 1956, added an extension of I-77 from I-85, through a rapidly growing corridor from Uptown Charlotte (along an upgrading of US 21 already under construction in some places), into South Carolina near Rock Hill. The highway under this plan was to continue to Columbia, South Carolina, terminating at an interchange with I-26. Collector–distributor ramps to both Alpine and Percival roads were proposed later on to more efficiently route traffic to and from the Fort Jackson military reservation and the I-77/I-20 corridors.
By the late 1970s, the southern terminus of I-77 near Columbia was amended to a grade-separated interchange with South Carolina Highway 12 (SC 12; Percival Road) with milemarkers signed accordingly. This extension was completed in 1986. That same year, the first phase of an Interstate spur (to be named I-326) between SC 760 (Jackson Boulevard) and I-26 was opened as far as SC 48 (Bluff Road). 1989 saw a two-mile (3.2 km) extension to the east, adding interchanges at Shop Road (later SC 768) and US 76/US 378 (Garner's Ferry Road/Sumter Highway).
The decision to extend I-77 from SC 12 and SC 760 (five miles (8.0 km) between the two roads) was made before I-326 was opened, so the southern portion was never signed as such, instead redesignated by the South Carolina Department of Transportation (SCDOT) as SC 478. The northern part of extension was completed as far as Forest Drive in early 1993, with the final three miles (4.8 km), including the SC 760 interchange, opened to traffic in 1995. The milemarkers and exit numbers for I-77 were adjusted accordingly as the extension was completed. As the Percival Road to I-26 section was under construction, southbound traffic on I-77 was detoured, by "Temporary I-77" signage, via I-20 and I-26 to bypass Columbia.
- South Carolina
- US 21 / US 176 / US 321 in Cayce
- I-26 in Cayce
- US 76 / US 378 in Columbia
- I-20 on the Woodfield–Dentsville CDP line
- US 1 in Dentsville
- US 21 south of Blythewood
- US 21 on the Lesslie–Rock Hill line
- US 21 in Rock Hill
- US 21 north of Fort Mill. The highways travel concurrently to Charlotte, North Carolina.
- North Carolina
- I-485 in Charlotte
- I-277 / US 74 in Charlotte
- US 29 in Charlotte
- I-277 in Charlotte
- I-85 in Charlotte
- I-485 in Huntersville
- US 21 in Cornelius. The highways travel concurrently to Mooresville.
- US 21 southeast of Troutman
- US 70 in Statesville
- I-40 in Statesville
- US 21 north of Statesville
- US 421 west-northwest of Hamptonville
- US 21 south-southeast of Jonesville. The highways travel concurrently to Elkin.
- I-74 west-southwest of Pine Ridge. The highways travel concurrently to the Virginia state line north-northwest of Pine Ridge.
- US 58 / US 221 in Woodlawn
- I-81 / US 11 in Fort Chiswell. The highways travel concurrently to Wytheville.
- US 52 in Fort Chiswell. The highways travel concurrently to Wytheville.
- US 52 west of Bland
- US 52 in Rocky Gap
- US 52 north-northwest of Rocky Gap. The highways travel concurrently to Bluefield, West Virginia.
- West Virginia
- US 460 east-southeast of Princeton
- US 19 south-southeast of Camp Creek
- I-64 southeast of Crab Orchard. The highways travel concurrently to Charleston.
- US 60 southeast of Snow Hill. The highways travel concurrently to Charleston.
- I-79 northeast of Charleston
- US 33 in Ripley. The highways travel concurrently to Silverton.
- US 50 east of Parkersburg
- SR 7 in Marietta
- I-70 south-southeast of Cambridge
- US 40 east of Cambridge
- US 22 northeast of Cambridge
- US 36 in Newcomerstown
- US 250 in New Philadelphia. The highways travel concurrently to south-southeast of Strasburg.
- US 30 / US 62 in Canton. I-77/US 62 travels concurrently through Canton.
- I-277 / US 224 south of Akron
- I-76 / SR 8 in Akron. I-76 and I-77 travel concurrently through Akron.
- SR 21 West of Akron
- I-271 in Richfield
- I-80 on the Richfield–Brecksville line
- I-480 on the Independence–Brooklyn Heights line
- I-490 in Cleveland
- US 422 in Cleveland
- I-90 in Cleveland
- Federal Highway Administration (October 31, 2002). "FHWA Route Log and Finder List: Table 1". Archived from the original on August 22, 2013. Retrieved March 28, 2007.
- "Cayce City Limits Map" (PDF). caycesc.gov. City of Cayce.
- AppalachianMagazine. "Virginia & West Virginia's Shared Tunnel | Appalachian Magazine". appalachianmagazine.com. Archived from the original on July 13, 2018. Retrieved July 13, 2018.
- Wighton, Doug (December 29, 2014). "Road trip: the alternate route to Florida". Toronto Star. Toronto Star. Archived from the original on March 20, 2018. Retrieved March 20, 2018.
- Exner, Rich (December 2, 2001). "Turnpike ramps to I-77 open tomorrow". The Plain Dealer. Retrieved June 16, 2008.
- "Ohio Turnpike, I-77 Interchange Opens To Traffic". WEWS-TV. December 3, 2001. Archived from the original on May 11, 2008. Retrieved June 16, 2008.
- Ohio Revised Code 5533.37 Archived October 1, 2011, at the Wayback Machine
- "Willow Freeway Archived June 12, 2010, at the Wayback Machine from Encyclopedia of Cleveland History
- Official Route Numbering for the National System of Interstate and Defense Highways, August 14, 1957
- Official Route Numbering for the National System of Interstate and Defense Highways, June 27, 1958