By road it's not a problem, by train it's only the same as having to change trains at Manchester to get to Bolton, or for example, people going to Old Trafford having to get off the train and then get a tram/bus.
I think ease of access is more a priority to home supporters - I'm sure there are probably people out there who don't consider going to as many City games because of hassle to get to/from the stadium each game. It may seem silly, but probably true.
I know loads of people that live in the East Riding that will say "Oh I'm not going all the way into Hull", but will happily drive all the way to Kingswood to go shopping.
Away supporters will go where ever the stadium is - they've already travelled across the country to see their team, so a few extra miles/train change isn't going to stop them.