York County needs $16M more for I-77 upgrades at one of the area’s worst traffic spots

York County will spend an extra $16 million to get one of its worst traffic spots fixed.

Cost increases at the Exit 85 interchange on Interstate 77 mean the county will divert money typically used to repave state, county and local roads. Exit 85 sits between Baxter and Kingsley, linking Fort Mill to Tega Cay across an interstate that also connects Rock Hill to Charlotte.

Civic and business leaders in the Exit 85 area have been clamoring for improvements there for years, as traffic routinely stalls at rush hours.

Traffic count sites on either interstate side of the interchange show 120,000 daily vehicle trips. Only the interstate at and between Carowinds Boulevard — the highest traffic count site in South Carolina — register more in the Rock Hill region. S.C. 160, which crosses the interstate at Exit 85, sees between 21,100 and 36,800 daily trips.

State and federal funding agencies working with York County ramped up interchange improvement efforts in the past three years. Those improvements have ballooned in costs over that time.

Coming up with the I-77 funding

York County submitted a letter to the South Carolina Transportation Infrastructure Bank in 2016 to request funding for Exit 85. That public agency assists with financing large jobs like interstate or bridge construction.

Updated requests led to a 2021 agreement where the infrastructure bank would provide more than $42 million for Exit 85 and $32 million for Exit 82 at Cherry and Celanese roads in Rock Hill. The deal committed York County to more than $7.4 million in matching funds.

Here’s how York County could chip in its share of $160 million of I-77 exit upgrades.

York County already contributed its portion, split between design and construction phases. Almost $46 million remains for the construction balance and waiting infrastructure bank money.

State Transportation Secretary Christy Hall sent York County manager David Hudspeth a letter this month stating construction will cost almost $92.7 million. That amount leaves a $46 million shortfall.

Hall wrote that the additional $16 million from York County could be spread across three years beginning July 1, 2024. It would be combined with additional funding from the Rock Hill-Fort Mill Area Transportation Study. The transportation group would use its own funding and a line of credit from the state transportation department to, along with York County’s portion, close the funding gap.

York County Council voted Dec. 18 to provide the extra $16 million. The transportation study policy committee voted Dec. 20 to provide $10 million more.

Kingsley, Baxter interchange cost increases

The high construction bid cost isn’t a surprise for area road planners.

Transportation study group administrator David Hooper told elected and road officials in May he’d heard a new cost estimate up $20 million. It was the second such increase in about 18 months. That total project estimate in May — construction is the biggest but not the full cost — put the project at more than $115 million.

‘How do we explain that?’ Price of planned work on I-77, SC 160 has more than doubled

The more than doubled cost from what was projected in the infrastructure bank application comes from several causes.

A significant one is a change in scope. The initial thought was for a diverging diamond construction similar to the first-in-state layout just north of Exit 85 at Interstate 77 and Gold Hill Road. Public meetings and engineering changed those plans to an alignment with flyover bridges and more vehicle capacity.

“What we’re doing here is a completely different animal,” SCDOT project manager Berry Mattox told the transportation study group policy committee in May. “This was always the more expensive of the options.”

Still, the configuration change only bumped cost estimates from about $50 million to $72 million. There’s also more widening of S.C. 160 in the current design that wasn’t part of the plans first sent to the infrastructure bank. Other increases come from higher asphalt and binder, labor and other construction costs.

“It’s death by a thousand cuts,” Mattox said in May. “Everything, incrementally, is going up.”

Traffic at Rock Hill I-77 exit could ‘double in every direction,’ planners say

How will York County pay for roads?

The additional $16 million in York County money will come through C-Funds. It’s the same source that provided the initial $7.4 million.

C-Funds are an annual allocation from SCDOT to each county in South Carolina from state gas tax revenue.

Counties have to spent at least 25% (plus all funds from a gas tax increase that started in 2017) on state highway system road construction, improvements or maintenance. York County Council typically spends remaining C-funds to pave neighborhood or local roads, among a range of transportation upgrades.

The forecasted amount of C-Funds in York County for the 2023-24 fiscal year is about $8.2 million. The county will have three years of C-Funds collections to generate the $16 million.