Suspect shutdown-related: IAD intl arrivals today Oct 22 was sending all Passengers to main terminal (midfield terminal customs closed), resulting in slower checked bag arrival and creating a bottleneck at customs exit as more pax than usual were rechecking bags for connection. I arrived early at 2pm and suspect by 4pm that alone could become a 30+ min wait to exit customs. If not rechecking bags, it was faster to stay to the right.