There are many “bad traffic days” on Atlanta’s roads, but an 18-hour stretch from Thursday, May 16th, and into Friday, the 17th, was absurd. In particular, the subsequent closures of I-75/northbound between McDonough and Stockbridge on Thursday almost entirely proved Murphy’s Law. This was a period for the ages, and the horror also broke out elsewhere. » RELATED: Gridlock Guy: When traffic is stopped and you need to go The gridlock started at approximately 10 a.m. Thursday, when a tractor trailer overturned on I-75/northbound at I-675 (Exit 227) in Henry County. The big rig stretched perpendicularly across the lanes and completely shut down I-75/nb. “(Thursday) was one of the most unusual middays I’ve ever worked,” WSB Triple Team Traffic’s Alex Williams said, still a bit aghast after processing the day. “We had a total of roughly four traffic RED ALERTS.” As we have covered here before, the WSB Traffic Team defines a RED ALERT as an interstate’s or major highway’s entire closure for an extended duration. For four such closures to happen near or at the same time is not a common thing. The first I-75/nb closure was bad enough, but just as it started clearing, a far bigger RED ALERT unfolded around noon. “I-75/nb south of Highway 20/81 in McDonough, which is south of the first RED ALERT, was shut down with a deadly crash & big rig fire,” Williams explained. The WSB Jam Cam showed a tractor trailer sliced open and engulfed in flames, obviously necessitating all of I-75/nb’s closure. The breadth of the wreckage made clear very early that this closure would last for hours. Then we learned that two big rigs actually collided and smashed a car between them, killing two. That meant an investigation extended the closure even later. There was correlation between the two wrecks, as the extreme backups from the first wreck created the traffic changes that galvanized the other. The Atlanta roads mirror NASCAR: cautions breed cautions. The I-75/nb shutdown in McDonough drilled traffic back into Butts County, before Highway 36 (Exit 201). Police diverted traffic off on the exits south of the crash and the side roads, especially Highway 42/23, became jammed. The extreme northbound commotion jammed I-75/southbound with onlooker delays all the way back to I-675. » RELATED: Gridlock Guy: How we decide where the WSB Skycopter flies The South Metro Express/Peach Pass Lanes stayed pointed in the northbound direction all the way through Friday morning. Crews near the crash before Hwy. 20/81 forced some traffic into those toll lanes, which worked effectively like an open freeway lane. Both the rubbernecking and the lack of relief the reversible lanes usually bring made for an evening commute that was an hour worse than normal on I-75/sb. And this was in the direction opposite of the closure. “What an unbelievable day for Henry County commuters,” WSB’s Veronica Harrell stated, after working those wrecks from the WSB 24-Hour Traffic Center. “I-75 northbound was shut down from 10:30 a.m. until well into the evening rush. I felt so sorry for everyone involved.” From the WSB Skycopter, I watched I-75/nb finally re-open just before our 6 p.m. Non-Stop News Feed. The cleanup of the two mangled and charred trailers on the right shoulder didn’t completely clear until around 10 p.m., WSB’s Steve Winslow observed. When monitoring major problems, like those on I-75 on the south side, losing sight of other problems is easy. Thankfully, Williams and Harrell did not. “I-285/northbound shut down at LaVista Road, so we had three RED ALERTS at once,” Williams recalled. “Luckily I-285 opened shortly after. Then, less than an hour later, I-20/eastbound shut down at I-285 in Fulton County.” But Williams and Harrell, and then WSB’s Smilin’ Mark McKay and Mike Shields, kept scouring the WSB Jam Cams and updating our Triple Team Traffic Alerts App with new problems. As soon as I-75/nb finally opened in Henry County, a vehicle flipped over on GA-400/northbound south of the Glenridge Connector. We arrived in the WSB Skycopter, just as a HERO unit spent about five minutes towing it to the right; traffic was awful back before Lenox. And to top off the rush hour, a devastating wreck shut down I-285/southbound at Atlanta Road (Exit 15) around 7 p.m. Thursday, keeping Shields busy through the evening. The wee morning hours of Friday saw Atlanta Police shut down I-85/northbound at Cleveland Avenue and I-75/85/sb at Highway 166, for crash reconstruction scenes. Those opened quickly. Then the south side got hit again with a three-hour RED ALERT at about 5:30 a.m. on I-675/northbound at Highway 42. The last hour of that closure saw half of I-75/northbound in Morrow, the main I-675/nb alternate, get blocked with its own wreck. McKay watched I-675/northbound open from the Skycopter after 8 a.m. We spell this all out to say that bad traffic happens with very little rhyme or reason. Drive alert and always prepare before your commute by checking our app, wsbradio.com, and keeping in tune with our live reports on News 95.5/AM750 WSB and Channel 2 Action News. If you don’t, you may find yourself saying, “Ohhh-ah,” as Harrell often does when the, uh, traffic hits the fan. » RELATED: Gridlock Guy: WSB Triple Team Traffic App helps navigate commute Doug Turnbull, the PM drive Skycopter anchor for Triple Team Traffic on News 95-5 FM and AM-750 WSB, is the Gridlock Guy. He also writes a traffic blog and hosts a podcast with Smilin’ Mark McKay on wsbradio.com. Contact him at Doug.Turnbull@coxinc.com.