Bridging the gap
Wed, 02/24/2021 - 9:07am
admin
Three key Daniel Island and Cainhoy peninsula connectors see repairs, possible expansions
By:
Zach Giroux
The 23 miles of interstate that connect Berkeley and Charleston counties, known as the I-526 Lowcountry Corridor (LCC), has been identified by the South Carolina Department of Transportation (SCDOT) as one of the state’s most congested highways. The stretch of asphalt is also one of the department’s top priorities to troubleshoot over the coming years.
It’s no mystery that the Lowcountry’s traffic woes have continuously been exacerbated by the constant boom in the area’s population and job creation. An average of 26 people move to the region daily, according to the U.S. Census Bureau.
In order to accommodate the growth, which is expected to increase 77% by 2050 according to the Berkeley Charleston Dorchester Council of Governments, infrastructure must budge. The efficacy of transportation has to advance in the hopes of a more hospitable state roadway.
In 2019, the state announced plans to double the width of the entire length of the corridor from four to eight lanes. This expansion would inevitably impact residential communities and businesses.
Since then, public surveys have been made available and studies are underway as state agencies and officials begin to address ways to make for a more efficient commute along the corridor east and west. Here’s where the project currently sits and where citizens stand:
I-526 LOWCOUNTRY CORRIDOR (EAST)
The LCC East project runs from Virginia Avenue in North Charleston to Highway 17 in Mount Pleasant. The distance between these two points encompasses 13 miles of roadway with approximately 20 minutes of commuting during ideal traffic conditions. However, rush hours and other types of traffic delays seem to be a daily trend morning, afternoon and evening.
More so, the two major river crossings along the route – the Don Holt Bridge (Cooper River) and the James B. Edwards Bridge (Wando River) – are anticipated to make planning and cost estimates a challenge. Although no official reports have been filed, some potential solutions include completely replacing the bridges or adding a parallel one.
In May 2020, SCDOT hosted an online questionnaire, followed by an online public information forum in July 2020 (see information boxes). SCDOT will be holding another public information meeting this summer, originally planned for this spring, to show the proposed improvement alternatives.
At this time, SCDOT managers and engineers have not fully reviewed or vetted the technical concepts that would be potentially advanced forward to the upcoming public meeting, according to SCDOT director of communications Pete Poore.
However, Poore noted that future plans will include “high level scale of potential right of way impacts.”
After this summer’s meeting, with no specified date and time, the project will move forward with a Planning & Environmental Linkages (PEL) study. An integrated approach that considers environmental, community, and economic goals early in the planning process and uses this information to streamline the transportation project development and environmental review process.
Results from the PEL study will then be carried forward into the next phase of the project development process, the National Environmental Policy Act (NEPA) process. This final analysis includes the identification of strategies and mitigation efforts to minimize the project’s potential impact to the community and natural environment.
This includes the purchasing of necessary right of way and establishing the project as a Design Build or Design Bid Build.
Design Build projects permit for the design and construction to begin and overlap with the right-of-way phase. Design Bid Build projects prohibit construction until the right of way and final design is complete.
The project’s PEL study was originally slated to take place this summer. Now that timeline looks closer to this fall or possibly later.
According to the LCC West project, which spans approximately 10 miles from West Ashley to North Charleston, the expansion is estimated to cost approximately $1.1 billion and affect 300 homes and businesses.
DON HOLT BRIDGE (COOPER RIVER)
The Don Holt Bridge, named after a member of the S.C. House of Representatives and insurance businessman, spans the Cooper River. The bridge consists of a parallel chord, three-span continuous, modified Warren-type truss bridge designed by the HNTB Corp.
The bridge provides a connection between the communities east of the Cooper River, including Mount Pleasant and Daniel Island, to North Charleston. It is also a major hurricane evacuation route for the area.
Following a lawsuit in the mid-1980s with the adjacent paper mill, over the fog produced by the smokestacks, it was mandated that a road weather information system be included in the Don Holt’s construction. The system uses variable-message signs and illuminating pavement lights, similar to a runway centerline lighting system, to detect reduced visibility on the bridge.
In June 2016, a $9.6 million painting contract was awarded and the installation of a containment system for the bridge truss began in June 2017. On July 19, 2017, one of the worst traffic nightmares in Lowcountry history became a reality.
Due to a combination of heavy rain and high winds, the tarp used for the paint job came undone. Then down came the Don Holt’s steel cables as they collapsed onto the roadway.
Seven vehicles were trapped under the tarp, but no injuries were reported, according to police reports. The bridge remained closed until the following morning.
Since that day, the Don Holt, along with the James B. Edwards Bridge, have undergone SCDOT maintenance activities part of the LCC East project including strengthening, water sealing, and 24/7 surveillance. SCDOT stated that numerous internal and external repairs have been made to all known deteriorations. All other maintenance is completed during nighttime lane closures.
BY THE NUMBERS
• Built: 1992
• Length: 27,065 feet
• Height: 155 feet
• Width (single
structure): 88 feet
• Number of vehicles per day, 2019: 74,200
JAMES B. EDWARDS BRIDGE (WANDO RIVER)
The James B. Edwards Bridge — named after a former S.C. governor, secretary of energy and long-time president of the Medical University of South Carolina — is locally referred to as the Wando River Bridge. The structure consists of a pair of precast, post-tensioned, concrete box girder bridges that span the Wando River between Mount Pleasant and Daniel Island.
The bridge was designed by Figg Bridge Engineers and is owned and maintained by the South Carolina Department of Transportation. The James B. Edwards was built to accommodate six lanes of traffic with narrow shoulders, but has only been used for four since its opening.
The James B. Edwards has a history of issues that arose during its construction. The construction contract ended in countersuits with SCDOT suing for delays and the contractor suing for design deficiencies. After a year-long investigation, no issues with the workmanship were found, which resulted in a $4.9 million settlement paid to
the contractor.
When the bridge was just four years old, the aluminum expansion joints installed began to fail. This would end up costing SCDOT $2 million in replacements.
On May 14, 2018, a failure of post-tensioning cables caused a closure of the westbound span. Weekly inspections of the 92 cables inside the bridge had been occurring since a repair project in 2016.
SCDOT officials discovered extensive corrosion and degradation to key parts of the bridge were caused by water leakage. The westbound span reopened to traffic more than two weeks later on June 2, 2018.
Months after the local traffic catastrophe, SCDOT released a 2,800 page engineering manifesto that November citing 14 recommendations to ensure the bridge meets its design life of 75 years. The installation of redundant post-tensioning cables was named as a top priority.
For more than a year, the aforementioned repairs have been occurring underneath the bridge. More than 100 feet of scaffolding is visible near the dog park and LTP-Daniel Island parking area.
BY THE NUMBERS
• Built: 1989
• Length: 7,900 feet
• Height: 138 feet
• Width (twin parallel
structures): 44 feet
• Number of vehicles per day in 2019: 71,700
ST. THOMAS ISLAND BRIDGE
The St. Thomas Island Bridge, named after late 17th century landowner William Thomas, was built to code in the late-1990s. But local historians suggest the bridge’s history dates back more than 80 years.
According to research from Daniel Island Historical Society’s co-founder Michael Dahlman, in 1940 there was a Ford Model T, a white truck and several tractors on Thomas Island. These vehicles most likely made their way over to the island via a bridge installed over the Wando River in 1939.
Before then, islanders used a narrow wooden plank that went above the marsh to get back and forth from Thomas Island to Daniel Island. Sometimes people would take a rowboat or ferry because the cost was cheap since it was not the primary way to transport people on and off of the island.
After American businessman and Daniel Island pioneer Henry Guggenheim purchased much of the island in 1946, many things changed including the roads and transportation. Then came the opening of I-526 in the early 1990s, followed by Daniel Island’s present day roads beginning in 1994.
Over a year ago, the bridge was patched and notably in need of major repairs. The City of Charleston is in the process of finalizing a new design contract with JMT Engineering.
As for the modern-day traffic records, the city does not currently have the means to report the number of vehicles that travel the bridge daily. A traffic study will be included in the bridge’s new design proposal slated to go before Charleston City Council in March.
BY THE NUMBERS
• Built: 1996
• Length: 95 feet
• Width: 32 feet (two 12-foot
traffic lanes)