My situation is a bit different from the one in the "Long commute, look for another job" thread.

My employer will be moving to a new facility in a few months, and my commute will go from reasonable to onerous. Moving close to the new location isn't an option. I've been with the company for several years, and I'd be perfectly happy to keep working there indefinitely, if only it wasn't for this move.

So, what do I say to an interviewer when asked why I want to change jobs? There's always the standard "seeking new challenges." I don't think I should lead with mentioning the commute, but dare I mention it at all?

FWIW, the job market is pretty good in my line of work. Thanks for your thoughts.