A new report from the Government Accountability Office has concluded that scores of commercial bus and tractor-trailer companies ordered to close because of safety violations remain in operation under new names. According to the report, at least 20 bus companies and nearly 1,100 trucking companies are believed to have dodged compliance that should have forced them to shut down. A commercial bus company blamed for a crash that killed 17 passengers in Texas last year was among the companies that changed named to avoid federal safety rules, the report said.