A19 Selby to Doncaster is wide in places, narrow in others, either way you'll get fast close overtakes in some places and traffic bunching behind you for ages in the lower limit bits. Best to take the TPT route, slightly to the east and crosses the Aire at Carlton. Or, you could wend your way to the west a bit and cross the Aire at Beal. If you pick TPT, check that all riders can do the off road bits, canal paths in Selby, broken potholed tarmac at Burn airfield, etc. etc.