Almost exactly one year after moving bus operations to Springfield Union Station, Peter Pan Bus Lines hosted an open house Tuesday to show off the new corporate offices upstairs from the bus berths and ticketing counters. “This is a very special place for Springfield,” said Peter A. Picknelly, chairman and CEO of Peter Pan Bus Lines. “For the thousands of people every day who visit our city utilizing public transportation, this is their first impression.” He said Peter Pan serves 75 cities across the Northeast and no cities of Springfield’s size have a comparable intermodal transit center. And bus business is up, he said. “Anytime we move closer to other modes of transportation, it helps us,” he said.