Two separate wrecks involving semi-trucks caused traffic tie-ups in Cumberland County Thursday morning. Around 3 AM, a wreck between two tractor-trailer rigs on westbound I-40 at mile marker 325 involved a 38-year-old male from Nashville and two men from Georgia, one 53 and the other 24-years-of-age. All refused transport to the hospital. Another wreck involving two other semis at mile marker 328 forced authorities to close down a portion of the interstate and reroute traffic into Crab Orchard and onto Highway 70 for a time. Again, those involved refused transport to the hospital.