1. Miami (MIA): 4.68 Hours
If you’re flying into Miami, don’t be surprise if you wait four hours to be processed by customs. In one year, more than 40,000 passenger waited for more than two hours to be processed at MIA. This airport comes in second place in international passengers but MIA is experiencing shortages in staff. For an airport with 72 inspection stations, only about 13 are open by 7 am. MIA is projected to bring in 10.5 million more people by 2012.