Route from Southampton Central to Weymouth, featuring SWR 444 and 450, as well as Cross Country 220 and 221 from Bournemouth to Southampton Central. Many potential service options, with express and stopper services available. Could even see some 166 from Great Western Express operating out of Weymouth and Southampton Central. Lots of stations along the line, good potential commuter line.
If we ever get another modern 3rd rail southern region route then I hope it would be something South West Trains/South Western Railway based around Southampton, either towards Bournemouth or Portsmouth with a Class 444/450. The Class 377 could also layer on at Southampton for services towards Brighton/London Victoria.
I will say though we'll need 455 moves and 701 tests as well just like IRL though if it comes to it that'll have to be Gen 9 exclusive.
I’d say that post is because that it could get boring with one double track mainline if the right railtours and freight services then it could be a bit boring with not much variety, although could be exciting still with the right layers and extra stock. Although, in my opinion, it’d be better to set the route in the early 2000’s when you had a mix of slam door stock, a few 450’s, Junipers and the 442’s that hadn’t yet been replaced