A new report on the cleanliness of subway lines has mixed results in the Bronx. The study finds that the 2, B and D lines are the dirtiest in the borough, while the 1 and 4 lines have gotten cleaner. The 5 and 6 lines, which serve eastern sections of the Bronx, were unchanged in terms of cleanliness compared to last year. The New York Public Interest Research Group Straphangers Campaign conducted the survey from September 2005 through January 2006.Related Information NYPIRG's Straphangers Campaign