Sentence:  After decades of complaint that cities are exploited by suburban commuters, the American metropolis is experiencing more and more <WSD>commutation</WSD> in the other direction. In some metropolitan areas, there is as much <WSD>commutation</WSD> out of the city as into it. 
Meaning of the word marked with <WSD> tags:  The process or habit of journeying to and from work on a regular basis; commuting.