The new structures will encompass three lanes of traffic in each direction, up from two, along the north-south freeway. In addition, the transportation agency plans to add shoulders on each side of the lanes as well as a pedestrian walkway, part of the statewide Palmetto Trail. (SCDOT rendering)
Construction of the new $350 million Interstate 95 bridge complex, which provides the only crossing over east-central South Carolina's Lake Marion, is planned to start in 2025 if the state Department of Transportation (SCDOT) receives federal grant funds.
The bridge is on a critically important route, handling more than 40,000 vehicle crossings each day, Justin Powell, SCDOT's chief of staff, told the Florence Post and Courier for an article that appeared Aug. 15.
The new structures will encompass three lanes of traffic in each direction, up from two, along the north-south freeway. In addition, the transportation agency plans to add shoulders on each side of the lanes as well as a pedestrian walkway, part of the statewide Palmetto Trail.
The project would replace the current four bridges along I-95 over Lake Marion, including a pair of large spans and two more smaller, relief bridges across the lake.
"[A new Lake Marion bridge is] very important for movement of national freight and traffic across the entire eastern seaboard," Powell said, noting that people in the Orangeburg County community of Santee and the Clarendon County town of Summerton, on the southern and northern sides of the lake, respectively, also depend on the span to get to jobs and health care.
Interstate 95 Bridges Rapidly Deteriorating
Portions of the I-95 bridges are currently in fair condition, according to SCDOT. However, the National Bridge Inventory analysis of future condition ratings shows in only two more years, the bridges will be in poor condition and may require load restrictions.
The bridge decks do not meet the current design standards for thickness based on design vehicle loads. In addition, the lack of proper bridge deck thickness results in a high rate of deterioration, especially on the I-95 corridor with its always-high percentage of heavy trucks.
Due to I-95 being a hurricane evacuation route as well as providing system linkage yielding high-capacity traffic, SCDOT noted on its website the interstate also cannot be closed and detoured at Lake Marion because the two nearest crossings are 20 mi. away. That means the bridges must be replaced while the current structures can still operate safely and functionally to maintain daily traffic demand.
SCDOT refers to the I-95 crossing at Lake Marion as a "mega-bridge." These are structures 55 years or older and not built to current state standards, such as having shoulders.
Powell said about two-thirds of bridges in the Palmetto State on interstate and primary routes are getting to the point where their repair or replacement needs to be considered.
The effort to replace the I-95 bridge across Lake Marion is part of the state's 10-year plan, adopted by SCDOT after the Legislature raised gas taxes and other fees in 2017.
By 2021, the agency was prepared to upgrade 500 bridges in the state by mid-2027, the Post and Courier noted at the time.
Plans Call for Several Critical Upgrades to I-95 Structure
SCDOT said the proposed I-95/Lake Marion Bridge replacement project would mean:
- Removal of the existing northbound and southbound I-95 bridges once the new structures are complete.
- Removal of abandoned in-water wooden pilings to the west of the current bridge structures.
- Two 12-ft. travel lanes would be provided in both the southbound and northbound directions.
- A 10-ft. minimum inside shoulder (shoulders may be wider due to staging requirements) and 12-ft. outside shoulder would be provided.
- A barrier-separated 14-ft. shared use path for pedestrians and bicyclists on the southbound bridge only.
- Bridge deck widths large enough to accommodate an additional 12-ft. travel lane in the future, if needed.
In addition, the design of the new bridge would allow for a water main to run between the two counties, the Post and Courier noted. A document from SCDOT said this would provide more economic development opportunities on the north side of the lake.
Construction of the 24-in. utility line would be the responsibility of the Lake Marion Regional Water Agency, which currently serves the counties of Berkeley, Calhoun, Dorchester and Orangeburg. Clarendon County, however, does not receive that same service.
Powell said crossing the lake had always been a hurdle for the group.
The bridge project comes as Lake Marion has become the site of more development. More than 400 houses and a hotel complex with a Charleston-based restaurant are on the way to the lake's shores, with state funds being used to support water infrastructure for the hotel.
SCDOT Hopes to Dramatically Cut Bridge Accidents, Detours
During the Clarendon County Council meeting Aug. 14, Bradley Reynolds, SCDOT's alternative delivery program manager, said the state agency is applying for multiple grants to provide more funding for the Lake Marion bridge.
The bridge has been shut down in the past to make repairs, he added, which results in a detour of approximately 70 mi.
No shoulders on the bridge means that when an accident does occur, the vehicles involved have nowhere to go. This can cause more accidents, he explained.
In fact, the bridge has been the site of 273 crashes since 2015, according to SCDOT data, seven of which have resulted in fatalities.
Other upcoming projects on I-95 include a 33-mi.-long road northward expansion from the Georgia border. SCDOT also is looking at rebuilding the interchange at I-95 and I-26 just a few miles south of Santee.
Additionally, the transportation agency is studying possible improvements for the I-95 bridge to the north in Florence County over the Great Pee Dee River, which is often threatened by flooding.
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