Flew back to Canada from the Caribbean last week through Newark airport. At passport control there were two separate queues, one marked for U.S. citizens and the other for foreigners. I attempted to use the foreigners lane but was told no, you should be in the U.S. citizen lane as Canadians are grouped with U.S. citizens at immigration. Is this the case at all U.S. international airports? Why isn't it clearly indicated on signage?