Potential
Durham train station to NCL. 18.5 miles as the crow flies and takes 50 minutes to an hour with a change onto the Metro. [using public transport]
Durham train station to LEA. 67.5 miles as the crow flies and takes 50 minutes to an hour with no change (if the train stops). [using public transport]
Newark (Notts.) to LEA 44 minutes (potentially)
This shows the potential (without any bearing to cost) for connection to other counties (Notts., Lincs. Durham, Northumberland etc) outside of Yorkshire.