Freeway crashes Friday morning slowed traffic heading to downtown from the north and the east.Crews were working at 8 a.m. to clear an overturned garbage truck on southbound Texas 121, the Airport Freeway, at the western edge of the bridge of the Trinity River. The crash, which occurred at about 6:47 a.m., caused traffic to back up to near Beach Street and closed several on ramps.Earlier, a crash was reported on southboudn Intestate 35 near Northwest 28th street that had traffic backed up to near Meacham Boulevard, according to radio reports.