We'll be driving north on I-95 on a Sunday morning from Fayetteville, NC to Alexandria, where we'll be staying for the week. When we leave Alexandria going back south, it'll be another Sunday and we plan to leave around 8am. I've been reading how congested I-95 is in Northern VA and wondering if we should get a E-ZPass Flex for our two trips coming and going to Alexandria. Also, would it help us driving into DC? If so, I'm hoping I could order the transponder to be mailed to us so we'll have it the Sunday we drive up. I appreciate your advice for our trip!