Carlisle - Sunderland (the Tyne valley route) is approx. 70 route miles as modelled. I have built the Durham Coast route southwards from there as far as Greatham, but this is still very much a 'work in progress' - ie, I don't think it's up to a good enough standard to be released yet. That's about 95 route miles as modelled. If I ever get to Middlesbrough, that would be 105 miles.