My suggestion is quite vast but I would like to see it added some day, I would like LNER Class 800/801 Azumas that travel from Grantham, Newark Northgate, Retford and Doncaster before branching off to Leeds (Calling at Wakefield Westgate) and York (non stop) and Northern 331 from Leeds - Doncaster (Calling at Leeds, Outwood, Wakefield Westgate, Sandal and Agbrigg, Fitzwilliam, South Elmsall, Adwick, Bentley and Doncaster), I would like it to be added to the game at some point. If not that is fine or if it is cut shorter that is also fine.
A very long route but not too many stations. In terms of variety of service there is no shortage! Would be a great ECML route to have. I think Peterborough would be a better starting point as more trains stop there and it's a larger town, and there aren't any stations between Peterborough and Grantham, so it's only one stop (but 30 miles).
This is a blinder of a suggestion, I'd love to have some/all of ECML as well as the local services. I think it'd be interesting to see a main route brought in concentrating on the ECML services, I'd be tempted to say run the line from Peterborough up to Doncaster with the Branches you mention to York and Leeds. and then bring in as additional Locos/routes focusing on the Doncaster/Leeds/York, filling in more stations and local traffic
It definitely would be nice to have the ECML to York and Leeds in TSW2. One of my most played routes in TS22 is a 3rd party freeware route called Leeds lines which goes from Doncaster to Leeds and then to York via Church Fenton and Garforth. There's also the ECML merge so you can do the full run from KX - Edinburgh and an extra merge which includes Leeds, Wakefield etc so you can do full runs from KX to Leeds or KX to York etc but also features the local services between Doncaster - Leeds and Leeds - York (TPE, Northern and Cross Country).
