Last night I was returning to Colorado from Phoenix on I-40 in Arizona. BNSF's transcon was backed up going eastbound starting just east of Flagstaff all the way to just  across the NewMexico state line. About 150 miles! There were a few gaps between a few trains of 3-4 miles but some were "nut to butt" 5 long. All them crews waiting for taxi's!Both tracks must have been blocked , I could'nt see at the site as it was just out of sight behind a hill from the highway.There was no back-up when I went through going westbound around 5am the same morning, so all that back-up took only 12-15 hours to accumulate. An example of just how busy that transcon is. I'd guess it will take days to get back to normal.Anybody hear exactly what happened?