I had the 'privilege' recently of an unplanned trip to Edmonton on a greyhound bus. It was actually a medical emergency (thankfully everything is okay ...) but I did have to endure a nine hour bus ride two nights in a row - one there and one back home again. It put a serious damper on my self imposed writing schedule. ( See my series on creating a writing schedule in 'The Writing Life') However, it also afforded some much needed reflective time.
In any case, I think it's good for writers to be thrust from their usual habits once in awhile. It gives a new sense of perspective, and I had the chance to observe lots of great characters which may appear in future writing. I also managed to do some reading, so all in all, it turned out to be a productive time. I think it's really about finding opportunities rather than seeing the negative in these kinds of interruptions.
And ... the best thing is, after two consecutive nights on a bus, I love my bed!!