Passenger traffic at Des Moines International Airport rose to 201,113 in January, up 3 percent from January of last year. Kevin Foley, executive director and general manager, said Southwest Airlines added some weekend flights halfway through January, but that wasn’t the biggest reason for the higher passenger numbers, part of a trend going back years. “We are growing,” Foley said. In fact, at times the airport — which has proposed a new terminal and other facilities — struggles to handle the rush at restrooms, baggage systems, and parking garages and lots, he added. Southwest’s January traffic grew 25 percent. American Airlines, the biggest carrier, saw 4.1 percent more traffic in January, compared with January 2017.