The journey time from York - Peterborough is around 1hr 15min covering a distance of around 112 miles. Again, this is quite a long route so it could be shortened. The stations on this line are: Peterborough, Grantham, Newark Northgate, Retford, Doncaster and York. Rolling stock on this route could include LNER Class 801/800 and LNER Class 91. It could also have a Class 66 for freight.
Hopefully track length isn't a great issue as there aren't many stations. Would be a great route though