This trap used to be very active (usually on weekday mornings was one of the ACE team Tahoes shooting laser here), but I passed through recently and it's still going. This empty weigh station is after the I-85/385 interchange, between that and Pelham Rd.
I was very surprised to see them out at 9:30 on a Sunday morning, though. Unmarked/tinted maroon CV backed up to the trees (probably their Sgt) shooting laser at NB traffic.
The chase cars go up through the abandoned weigh station (what is funny is that they move the "closed" signs in order to be able to run their speed operation) and up to the on-ramp from the weigh station to interstate. They like to pull people very shortly after the weigh station so that when the stop is complete, the officer can either drive the wrong way on the shoulder, or reverse back to the weigh station and not have to go the long way to turn around.
Heads up if you're traveling NB on I-85 through Greenville County.