A Canadian National railway bridge spanning Chebucto Road near the Armdale Rotary appears to be crumbling, says a Halifax man.

The man, who did not want to be named, said he was stunned when he was hit by a shower of concrete gravel as he walked under the bridge Thursday afternoon.

"I was lucky I was wearing a hat. A big chunk also fell and just missed me."

He said he has contacted CN about the problem as well as the National Transportation and Safety Board and Halifax Regional Municipality's public works department.

"Something has to be done about this right away. A child or a car passing under the bridge could be struck."

The railway overpass, built in 1917, spans one of the busiest traffic routes in and out of the city.

Thousands of vehicles pass under the bridge daily, coming from or heading toward St. Margarets Bay Road and Herring Cove and Purcells Cove roads.

The bridge is also part of the sole rail artery serving the Halterm container pier.

Lengthy repairs requiring closure of the bridge and rerouting of traffic would cause a transportation nightmare for shippers and commuters.

CN, not the city, is responsible for maintenance on the railway's numerous overpasses located throughout metro, said Jeff Spares of HRM's public works department.

He said he contacted CN about the latest incident involving the bridge's crumbling concrete wall.

The overpass actually looks worse than it is, he said.

"Structurally, (the bridge) is OK. But it appears it needs some work. There's some loose concrete and that's not good."

However, CN spokesman Pierre LeClerc said all concrete sections were intact during a Dec. 13 inspection of the entire structure.

"It is good that we received that information. We are going back to re-evaluate (the bridge)."

He acknowledged the appearance of the bridge is not "esthetically pleasing" but that the structure is sound.

Should maintenance need to be carried out, it is unlikely the rail line or street beneath will need to be closed, he said. "Usually, scaffolding is used and there isn't any need to reroute traffic."

Last summer, CN performed maintenance work on the Young Street railway overpass with little inconvenience to users.

Halifax Port is aware a safety concern was reported, said spokeswoman Patricia MacDermott Friday. If repairs are required, they "are not likely to have an adverse impact on rail traffic," she said.