That line twists and turns through County Durham and then make a couple of even sharper looking turns before they approach Durham city. Then after Durham there is another particularly wheel scraping corner before Chester-le-Street. It's not exactly crawling speed, but it's not overly fast either. What makes it worse is the A1(M) motorway passes along the same corridor on a much straighter alignment. It's a pity when that motorway was being built the opportunity wasn't taken to realign the ECML alongside it. Although accessing Durham will always require that dog leg route after Ferryhill.Yes, north of Darlington, that is much faster than is possible at present.