A large paving machine that broke down during work on the Theodore Roosevelt Bridge yesterday helped to cause a massive traffic tieup in the District of afternoon rush-hour traffic headed into Virginia, D.C. police and city officials reported.

Blocks-long backups were reported along all major arteries that feed the Arlington Memorial, Roosevelt and Key bridges, including Independence, Constitution and Pennsylvania avenues NW, and many intersections neared gridlock conditions.

Traffic was reported to be particularly snarled on approaches to the Key Bridge, including K and M streets and the elevated Whitehurst Freeway. One commuter reported spending an hour to drive from 16th and M streets NW to Wisconsin and M streets NW in the heart of Georgetown.

George W. Schoene, city traffic services chief, said the broken equipment was a large asphalt-laying machine that occupied an entire outbound lane of the Roosevelt Bridge.

The machine was being used for "very minor" patching or other resurfacing work when it broke down, Schoene said. "They had to repair it there on the bridge because it's so big," he added. Normally such repair equipment is removed before rush hour starts.

The malfunctioning device was removed from the bridge about 5:30 p.m., Schoene said.