At some point, York County drivers are going to have to learn to move differently, or sit still.
To avoid gridlock in already congested areas, road planners must think differently, and so do drivers.
"We're challenging people's expectations of how we move today," said David Hooper, administrator of the Rock Hill-Fort Mill Area Transportation Study.
RFATS policy committee last fall approved funding for a study on traffic along the I-77 corridor. Rock Hill representatives gave in on a controversial new bridge crossing of the Catawba River that repeatedly met opposition on the Fort Mill side. In exchange, the first phase of the study would focus on Rock Hill interchanges including Celanese, Cherry and Cel-River roads.
That study is in its early stages, but data coming in shows what drivers likely know or expect. Population is increasing. Wrecks are happening more often at choke points, the stop-and-go connections to I-77, than elsewhere.
"I'm very confident we will see comparable outcomes on Gold Hill Road and (S.C.) 160 and other areas," he said.
Still, traditional road widening won't always work, like on part of Celanese that has among the worst traffic in the county on a stretch of seven lanes.
"You have to keep climbing the ladder," Hooper said of options.
One question in the study involves "smarter" traffic signals, able to change with traffic conditions in real time to keep vehicles in motion. Similar signal timing has worked elsewhere, but typically in smaller areas.
"This type of equipment probably isn't going to get us where we need to be," Hooper said.
Other options like consolidating driveways and eliminating turns could be difficult for drivers, or property owners. Having signals that cycle quickly to green on feeder roads could go away. Hooper said it doesn't make sense for two cars on a small street to trigger a green light and stop a dozen cars on the arterial road.
"Some of that's going to have to give," he said.
The number of vehicles on a road compared to what it was designed to handle, such as Cherry and Celanese roads connections to I-77, are largely failing or close to it, the study says. With a 30 percent population and employment jump expected in less than three decades, all of them are expected to have a failing grade.
Separate from the study, RFATS is part of a larger Charlotte transportation system that has to set federal goals for traffic issues. Last year drivers in the Charlotte region spent an average of 18 to 20 hours per year going 60 percent of the speed limit (or 20 mph) or less.
The goal for 2022 is 27 to 34 hours a year. York County isn't helping.
"The intensity of the congestion down here, it's much greater than at some other places in the region," Hooper said.
There are options, but they won't be easy. Diverging diamond, "superstreets" and fully displaced lefts are all variations of a similar thought — traffic moves better when people don't turn left.
"You're limiting left turns," said Scot Sibert, consultant working with RFATS.
Without left turns — drivers would turn right, then U-turn — intersections wouldn't have to cycle through eight green lights at a time. Experts say taking out left turns could equate to a 20 percent reduction in traffic flow. Problem is, existing intersections aren't built that way.
"It has a price tag," Hooper said.
Reorienting the India Hook and Celanese roads intersection could cost $8.3 million. Anderson and Cherry roads could be $7.7 million. Intitial study data shows it might cost $50 million to change six critical interchanges.
"If you're going to get the benefit down the corridor, you're going to have to look at more than one location," Hooper said.
Long-term, though, conversions may help.
"It has proven that it does work," Sibert said.
Beyond taking turns out, road planners will have to keep finding innovative solutions. For example, a one-way connection from I-77 to Mount Gallant Road in the Rock Hill area could take 3,100 vehicles per day off of Celanese, according to the study.
"There's a reduction on Sutton (Road in Fort Mill) as well if that intersection is constructed," Sibert said.