An ice jam is causing traffic troubles in Cedar Rapids.Motorists who normally use Ellis Boulevard had to find a detour this morning as the road was closed due to do problems with ice. The Cedar River, which runs through Cedar Rapids, had ice eight-to-ten inches thick last night, but it was stuck along a bend in the river and the ice jam caused flooding. Up to eight inches of water was on the roadway and it was starting to freeze in the low temperatures. Crews sandbagged other roads overnight as a precaution.