Both these routes have previously been fine on the same computer. Whilst I have been unable to try every single route in my TS installation, the issue is also affecting Newcastle York (default) and Bristol Exeter (Just Trains). I have used all of these routes over the past few days with no issue and have made no changes to my graphics settings either in-game or using the AMD Catalyst Control Centre.
I have deleted the cache in-game and have also re-verified it using steam yet the problem persists. The only change that has occured is Steam downloading approx 100mb of data this evening when it loaded, but I don't know what it was for and can't really see a reason for this to occur as a result.
Any ideas?