York is a marvelous place to visit and the station is a marvel to look at. Darlington is already in the game in Tees Valley Line and if they expanded the route and it will need a massive update to update and expand the route. Scarborough is a small terminus in North East England. York to Darlington is 55.3 miles and even passes the NRM so you maybe able to see some preserved trains if it's past 1980. York to Scarborough is 40 miles so in all it is a 95.5 ish miles making it the longest UK route. York Station Darlington Station Scarborough Central Station
BR Blue Era You can use every BR Blue diesel 08 40 47 101 45 31 BR Class 55 'Deltic' BR Class 50 This one's at Kingswear
Modern Era Jubilee and 8F railtour (Scarborough Flyer) Class 801 AI Class 66 TransPennine Class 802 TransPennine Class 68
In the British blue era this can simply merge with Tees Valley Line forming the BR Northeastern Region network if both were 1989 at Darlington