Whenever trains rattle across the railway bridge over King Street in Alexandria, grit and dirt settle on the pedestrians and cars underneath.

When it rains or snows, water leaks out of the gutters along the pedestrian walkway, staining the newly cleaned walls, and forms puddles in the summer and sheets of ice in winter.

The metal bridge that serves as a gateway into Old Town is so rusted that the paint is peeling off in huge flakes and several small cross supports are broken.

City officials say that the bridge, which was built in 1905, is an eyesore and a safety hazard and that they want it and a companion crossing over Commonwealth Avenue cleaned up.

"How is it possible that it deteriorated to such a level?" asked City Council member David G. Speck, who said he found a five-inch metal spike lying beneath the bridge during one recent visit. "Where did that come from? Stuff has got to be falling on people and cars."

More than 3,000 pedestrians and 18,000 cars cross beneath the King Street bridge each day, so Speck decided about a year ago to make cleaning up the area his next crusade.

But he and city officials have discovered that the task may prove more daunting than they had imagined.

The bridge, it turns out, belongs to CSX Corp., a national railway company that owns nearly 10,000 crossings nationwide. CSX officials said that the company inspects its bridges at least once a year and makes necessary safety improvements but that they are loath to spend money on improvements they see as purely cosmetic.

"We're one of the most capital-intensive industries in the nation, and we make a choice to invest in the track for safety and operations, not aesthetics," said CSX spokesman Robert L. Gould.

But city officials say they believe the rusting cross supports and the groundwater that leaks through the retaining walls do pose a safety hazard.

The city's director of transportation and environmental services, Richard Baier, said he is concerned that the ground around the bridge may be less than solid and that the disconnected cross supports might make the structure vulnerable to cracks.

Gould countered that the King Street and Commonwealth spans are inspected regularly and are sound. The bridges are central to virtually all rail travel between the Northeast and Southeast. Amtrak, Virginia Railway Express and CSX's freight trains all use the tracks.

"I am not aware that safety is in any way compromised," Gould said. "We can't operate trains on these bridges unless they are safe."

But city residents and visitors may not be as safe as the trains, city officials and residents said.

"From a pedestrian standpoint, it is unsightly blight," said architect Marlin G. Lord, who chairs a citizens group looking at pedestrian access in the area. "It is really unpleasant having to walk through oozing seepage with poor lighting. It's very unsafe."

The underpass is dark and threatening at night, and the flakes falling off the bridge include asbestos and lead, city officials said.

"I'm always looking up to make sure that nothing is falling on me," said Ashley Spencer, treasurer of the Upper King Street Neighborhood Association. "We are really concerned with the unsightliness."

In addition, the city receives several claims each winter from pedestrians who say they have slipped and fallen on the ice patches formed from leaking rain and groundwater, Baier said.

CSX officials said they have no record that either pedestrians or cars have suffered harm related to the bridges.

City officials first approached CSX about problems with the spans in June 2000. After a year of negotiations, CSX recently removed a broken wooden catwalk at a cost of $3,400. The company is also replacing the leaking gutter on the north side of the King Street bridge, Gould said.

For its part, the City Council approved spending $4,000 to clean and repaint the walls on the side of the bridge. But the water stains reappeared shortly after the work was done last fall, city officials said.

Now the City Council wants CSX to do more. Specifically, the council would like the entire bridge repainted, the crossbeams reattached and a cover installed over the pedestrian sidewalk on the north side of King Street to match the one on the south side.

"We would be open to participating in a joint venture or some type of partnership, but we've got to overcome CSX's blatant unwillingness to work with us," said Mayor Kerry J. Donley (D).

CSX officials said that the falling flakes aren't dangerous and that they are looking at whether large chunks fall often enough that chicken wire should be installed to protect pedestrians and cars. But company officials draw the line at spending company money to repaint the bridge span.

Federal rules on asbestos and lead paint mean that the entire structure would have to be covered with a tent during the work, making it very expensive.

"If it's a safety issue, we're going to address it, but [otherwise] we're looking at resources and making decisions about where best to spend our capital," Gould said.

That argument doesn't fly with Speck.

"Yeah, they do have a lot of bridges, but they're supposed to be maintaining them," he said. "You get the feeling that CSX is just giving the city the giant finger."

City and CSX officials are working together to seek a $500,000 grant from the $25 million federal Transportation and Community and System Preservation Pilot Program to cover the cost of repainting the span. But they probably won't hear until fall whether their application has been approved. In addition, the grant process is competitive, and there's no guarantee the project will get the money.

In the meantime, city officials said they cannot help comparing the CSX bridges with the Metro crossings just a few feet east. Metro's cement bridges -- which are much newer -- are clean, and pedestrians walk beneath them on neatly swept tiles.

If negotiations break down entirely, Baier said, the city will consider declaring the bridge a blight and try to use building code regulations to force a cleanup. But that method could face serious legal hurdles, so city officials would prefer to find a way to work with the railway company.

"We're just looking for a willing partner," Donley said.

The bridge carrying the railroad tracks over King Street, above, was built in 1905 and has aged to the point that the City Council considers it an eyesore and a danger to pedestrians and wants it cleaned up.Mayor Kerry J. Donley (D) walks beneath the King Street bridge, for which he says CSX Corp. so far is unwilling to cooperate in making improvements -- chief among them being the repair or replacement of broken and rusted crossbeams, above, and the elimination of leaks from above. CSX officials do not view falling flakes of paint, or any of the other problems city officials have cited, as safety hazards that need immediate attention.The city had the walls under the bridge cleaned and repainted last fall, but water stains reappeared.