Yesterday I traveled through most of Virginia on the I-66 and the I-81, from Washington to near Front Royal past Harrisonburg to Staunton. We stopped several times and exited the freeway for food and things we had to do.
I was amazed that TMO coverage while not 100% or equal to Verizon, was awfully good. I could use my BB most of the trip even off the freeway in rural areas. I am sure that a few miles away from the freeway, unless you are in Harrisonburg or Staunton, you will lose signal, but still, it was impressive.