ok. firstly, that route is far too long for the game (Euston to Milton Keynes is just long enough). can you give us some more information about the route.. You have already stated that you would like AWC on the route but is there any other companies? Freight? what about layers?
There is no maximum route lenth. So actually it could be made. It just needs commuter services as well
Could doesn't mean would. Dovetail have explained many times why they will not do a route that length. Not only would it take an insane amount of time to build (currently the relatively short routes take about 9 or 10 months, so this would take up to two years to complete, maybe more), very few people would actually drive the whole route, so there is no point in DTG making a route that would take four hours to travel across when most players get bored after one hour. London to Birmingham or Glasgow to Carlisle would be more than long enough for the vast majority of people.
London to Manchesters is 2 hours 12 minutes, so no longer than then the longest runs on SH, CJ or SPG The issue is distance and stations, longer then SKA by 50miles with a lot more stations to model.
Being from the UK myself this is certainly a route I would love to see although I’ve seen plenty of comments saying it’s highly unlikely but we can only keep our fingers crossed!!
Definitely Glasgow/Edinburgh-Carlisle as its a very interesting route with all the hills and stuff. Going further down to Oxenholme allowing players to go up Shap summit and traversing the Cumbrian mountains in a tilting Class 390 or 221 would in my opinion be a good expansion and experience for players.