Interstate 526 Explained

State:SC
Type:I
Route:526
Map Custom:yes
Map Notes:I-526 highlighted in red; future section in blue; unbuilt future section in orange
Alternate Name:Mark Clark Expressway
Length Mi:19.56
Length Ref:[1]
Counties:Charleston, Berkeley
Direction A:West
Terminus A: in Charleston
Junction: in North Charleston
in North Charleston
Direction B:East
Terminus B: in Mount Pleasant
Established:1989
Spur Type:I
Spur Of:26
Previous Type:SC
Previous Route:522
Next Type:SC
Next Route:527

Interstate 526 (I-526) is a 19.56miles auxiliary route of I-26, providing a partial beltway around Charleston, South Carolina, in the United States. The route serves several purposes, firstly, as a bypass for through traffic on U.S. Route 17 (US 17) to avoid downtown Charleston, and, secondly, for traffic on I-26 bound for the coastal towns located north and south of Charleston. The route is not yet complete, as the western terminus it is planned for the route to be extended an additional 10miles. After the eastern terminus, the roadway continues as a short business route, known as Interstate 526 Business (I-526 Bus.).

Route description

I-526 begins at an incomplete interchange with US 17 (Savannah Highway) and South Carolina Highway 7 (SC 7, Sam Rittenberg Boulevard) in the West Ashley section of the city of Charleston, just north of the Stono River. The interchange includes a loop ramp from northbound US 17, a ramp from southbound US 17, and a half-diamond interchange with SC 7. The four-lane freeway heads north past the Citadel Mall and meets SC 461 at a partial cloverleaf interchange. SC 461 heads west as Glenn McConnell Parkway and east as Paul Cantrell Boulevard; both directions lead to SC 61 (Ashley River Road). I-526 crosses SC 61 and uses the General William C. Westmoreland Bridge to cross the Ashley River into the city of North Charleston. The freeway has diamond interchanges with Leeds Avenue and SC 642 (Dorchester Road) and crosses over CSX's Charleston Subdivision.

I-526 continues through a connected pair of half-diamond interchanges with Montague Avenue and International Boulevard. Both streets lead to the North Charleston Coliseum and Charles Towne Square; the latter one is the access road for Charleston International Airport. The Interstate curves east and reaches its junction with I-26, which is a cloverleaf interchange except for a flyover ramp from eastbound I-526 to westbound I-26. I-526 crosses over Norfolk Southern Railway's SC Line and has a partial cloverleaf interchange with Rivers Avenue, which carries US 52 and US 78. The Interstate continues from its overpass of the U.S. Routes as a viaduct above wetlands along Filbin Creek. The viaduct crosses over the CSX rail line again and has a four-ramp partial cloverleaf interchange with Rhett Avenue and a half-diamond interchange with Virginia Avenue. The Rhett Avenue interchange includes a U-turn ramp that allows access from westbound I-526 to Virginia Avenue and from the avenue to eastbound I-526.

I-526 crosses the Cooper River on the high-level Don N. Holt Bridge and enters the Daniel Island section of the city of Charleston in Berkeley County. The freeway has partial cloverleaf interchanges on either side of Beresford Creek with Clements Ferry Road and Seven Farms Drive/River Landing Drive. Both interchanges lead to Blackbaud Stadium, home of the Charleston Battery, and the Family Circle Tennis Center, home of the Family Circle Cup. I-526 continues southeast across the Wando River on the James B. Edwards Bridge back into Charleston County and the town of Mount Pleasant. The freeway has a partial cloverleaf interchange with Long Point Road and curves south at Hobcaw Creek. I-526 has a partial flyover interchange to and from US 17 in the direction of Georgetown before the Interstate reaches its eastern terminus at a partial cloverleaf interchange with US 17 (Johnnie Dodds Boulevard). The highway continues as I-526 Bus., a four-lane highway that follows Chuck Dawley Boulevard to SC 703 in the center of Mount Pleasant.

All of I-526 is included as part of the National Highway System, a system of roadways important to the nation's economy, defense, and mobility.[2]

History

Planning of the freeway dates back to the 1960s; construction on the first section began in 1979. Opened in 1982 as an unnumbered freeway, it traversed from Ashley River Road (SC 61) to Leeds Avenue, crossing over the Ashley River.

In 1985, the freeway became SC 31, connecting US 17/SC 7 to Dorchester Road (SC 642). By 1987, it extended to International Boulevard, providing access to the Charleston International Airport.[3]

In 1989, the freeway was rechristened as I-526 after it connected with I-26 (exit 212). In 1992, I-526 was extended east over the Cooper River to Daniel Island, then over the Wando River to Mount Pleasant and its current eastern terminus with US 17 and I-526 Bus.[4]

In 1993, the Robert B. Scarborough Bridge was opened, connecting downtown Charleston with James Island; it is signed as SC 30. Since 1993, several residents and groups in the area have fought against the completion of I-526, which will connect both James Island and Johns Island.[5] [6]

Future

The proposed missing section of I-526 was the subject of an environmental study that was completed in early 2014.[7] Various alternative routings and options are being reviewed, but the general plan is to extend south from US 17 to Johns Island and then east to James Island, where it will connect with SC 30 (possibly renumbering it). Some alternatives shown include the possibility that it will be built in expressway grade instead, falling short of being labeled an Interstate Highway.[8]

Citing Charleston County's inability to provide funds to cover the project's increased cost, the State Transportation Infrastructure Bank (SIB) board voted on May 26, 2016, to abandon the proposed extension of I-526 across James and Johns Islands.[9]

In 2021, SCDOT revived the 526-extension project. As of May 2023, they are aiming to start construction by 2025.[10] [11] In December 2023, the South Carolina Joint Bond Review Committee approved the state's Transportation Infrastructure Bank's action Tuesday afternoon of providing $75 million for preliminary costs in the project, which is dubbed the Mark Clark Extension Project.[12]

Interstate 526 Business

State:SC
Type:BS
Route:526
Location:Mount Pleasant, South Carolina
Formed:1992
Length Mi:1.570
Length Ref:[13]

Interstate 526 Business (I-526 Bus.) is a 1.57miles four-lane boulevard-grade business spur of I-526 along Chuck Dawley Boulevard between Johnnie Dodds Boulevard (US 17) and Ben Sawyer Boulevard (SC 703).

I-526 Bus. is not part of the National Highway System.[2]

See also

External links

Notes and References

  1. Web site: 2018 . Table 2: Auxiliary Routes of the Dwight D. Eisenhower National System Of Interstate and Defense Highways as of December 31, 2018 . Route Log and Finder List . . January 22, 2022.
  2. Web site: National Highway System: Charleston--North Charleston, SC. https://web.archive.org/web/20151017132129/http://www.fhwa.dot.gov/planning/national_highway_system/nhs_maps/south_carolina/charleston_sc.pdf. dead. October 17, 2015. United States Department of Transportation. October 1, 2012. August 14, 2013.
  3. . General Highway Map, Charleston County, South Carolina . PDF . SCDOT . 1987 . May 20, 2013.
  4. . General Highway Map, Charleston County, South Carolina . PDF . SCDOT . 1996 . May 20, 2013.
  5. Web site: I-526 Extension . Coastal Conservation League . July 28, 2010 . September 19, 2011.
  6. Web site: So Much to Lose For So Little Gain . Nix 526 . September 19, 2011.
  7. Web site: SCDOT - I-526 - Welcome to the Mark Clark Expressway! . SCDOT . September 30, 2010 . May 20, 2013.
  8. PDF. Staff . RPA Overview . Mark Clark Expressway Environmental Impact Study . South Carolina Department of Transportation . May 20, 2013.
  9. Web site: S.C. agency moves to walk away from Charleston's I-526 extension.
  10. Web site: The Latest- Mark Clark Extension. South Carolina Department of Transportation. April 22, 2022.
  11. News: Harris . Anna . SCDOT breaks down the costs of the I-526 extension . 20 July 2023 . www.live5news.com . 27 January 2023 . en.
  12. News: Johnson . Emily . SC Committee approves $75 million toward I-526 extension, includes stipulation . 10 March 2024 . www.live5news.com . 5 December 2023 . en.
  13. Web site: Highway Logmile Report . South Carolina Department of Transportation . December 14, 2020 .