Just getting onto I-85 can be frustrating for commuters using the Jimmy Carter and Pleasant Hill interchanges. Traffic sometimes backs up nearly half a mile to turn left onto the interstate. Drivers who aren’t trying to get on to the interstate also endure long waits to get across the bridges.
“The traffic is bumper-to-bumper” on Pleasant Hill Road, Tobin said.
Completely new interchanges would help but would cost tens of millions of dollars. Instead, Gwinnett officials will use a relatively cheap fix: They’ll spend about $8 million to convert the two bridges into “diverging diamond” interchanges.
Under the design, traffic on Jimmy Carter and Pleasant Hill will be routed into the left-hand lanes across the I-85 bridges before switching back to the right-hand lane on the other side. Gwinnett officials say the design will make it easier for motorists to turn left onto I-85, reducing congestion and improving safety.
It’s a design first used in Missouri in 2009 and adopted since then in a handful of other U.S. locations. The first diverging diamond interchange in Georgia — at the intersection of Ashford-Dunwoody Road and I-285 — will be finished this fall.
Gwinnett Deputy Transportation Director Alan Chapman said construction on the Pleasant Hill interchange should begin in late spring, with work on Jimmy Carter to follow later this year. Construction should last nearly a year.
The new interchanges are not expected to affect traffic on I-85 itself. But they’re part of a larger effort to keep traffic moving along the I-85 corridor.
Gwinnett County also is studying whether it makes sense to spend $257.5 million to connect Ronald Reagan Parkway to I-85. The four-lane divided highway now runs from Snellville to Pleasant Hill Road, three miles short of the interstate.
The county also is conducting a $1.1 million study of transit alternatives — including light rail and bus rapid transit — along the I-85 corridor.
The redesigned interchanges are small compared with those projects. But Chapman said the redesign should delay the need for completely new interchanges by a decade. And local business leaders see other benefits.
Joe Allen, executive director of the Gwinnett Place Community Improvement District, said reduced traffic congestion at the Pleasant Hill interchange could attract shoppers and encourage new business development.
“We really see this as a spark for Gwinnett Place’s revitalization,” Allen said.
County officials have held public meetings to prepare commuters and nearby owners for the unusual intersections. Chapman said the county will do more to educate drivers as work on the interchanges progresses.
“We know there will be some concerns because it’s different,” he said. “It’s something drivers will have to get used to.”
Tim Le, owner of Atlanta Maxim Realty International near Jimmy Carter Boulevard, initially thought the diverging diamond was “kind of complicated.” But now he’s sold. He said traffic often backs up on Jimmy Carter, blocking access to local businesses.
“When I learned what it was supposed to do and how it’s going to relieve the congestion, I’m very happy about it,” Le said.
Gwinnett County has solicited applications from contractors interested in revamping I-85 interchanges at Jimmy Carter Boulevard and Pleasant Hill Road. The applications are due Feb. 7. The county will solicit formal bids on the Pleasant Hill interchange in early spring, with work starting in late spring. The county expects to solicit bids on the Jimmy Carter project by June, with work starting later this year.