The westbound span of the Chesapeake Bay Bridge. (Ricky Carioti/WASHINGTON POST)

A partial closure of the Chesapeake Bay Bridge during the coming holiday rush was averted Tuesday after bridge officials said an emergency inspection of the westbound span found no safety problems.

The Maryland Transportation Authority had shut down the three westbound lanes late Monday but reopened them to traffic at noon Tuesday. Workers who were sandblasting and painting the bridge late Monday night had reported that they saw “unusual and slight vertical movement.”

The 4.3-mile suspension bridge is designed to have a certain amount of flexibility and movement, but “what was reported was a little more than usual,” said Harold Bartlett, the authority’s executive secretary.

Bartlett said inspectors found no structural problems on the bridge’s surface or underside. The inspectors, he said, determined that any movement was caused by “a unique wind pattern” coupled with the “containment system” that prevents painting-work debris from falling onto the road. That system includes large tarps that had the effect of a sail in the wind, creating an “uplifting effect” on the bridge, Bartlett said. He said the bridge did not suffer any structural damage.

“We have convinced ourselves that the bridge is now perfectly safe to open,” Bartlett told reporters before the bridge reopened.

Authority officials cited the Bay Bridge as well as other aging bridges, tunnels and highways in need of rehabilitation as the basis for a statewide toll increase last year. As in other states dealing with decaying infrastructure, some Maryland facilities date back more than 70 years. The Bay Bridge’s westbound span opened in 1973, and the eastbound span opened in 1952.

Morning traffic was diverted onto the two-lane eastbound span, causing a backup for miles in both directions. By midmorning, westbound bridge traffic had backed up seven miles. Eastbound traffic also backed up several miles as all eastbound traffic was stopped for 11 / hours to try to allow the westbound backups to dissipate.

News that the bridge would be fully open in time for the onslaught of holiday traffic later this week brought sighs of relief to Eastern Shore officials. The bridge is a major connector for beachgoers, as well as daily commuters, freight traffic, seafood distributors and Eastern Shore residents trying to reach Baltimore area hospitals. Driving around the bridge adds at least two hours, which would double the travel time for many trips.

“Yay! That’s good news for everybody!” Carol Everhart, president of the Rehoboth Beach and Dewey Beach Chamber of Commerce, said when she heard the news that the westbound span would reopen. “Anytime we lose a connector to the resort area, especially on a high- visitation weekend, it has an economic impact.”

Everhart noted that many hotels have a two-night minimum and no-refund policy for busy holiday weekends. Labor Day is one of the busiest of the year, she said.

Easton Mayor Robert Willey said that even closing the bridge for a day or two would be “serious.” While most frequent bridge travelers know to expect delays during July and August, he said, Tuesday’s temporary closure should renew attention from emergency management officials about the Eastern Shore’s dependence on the bridge.

“We need to look at: How would we handle something like this?” Willey said.

Traffic is backed up in this traffic camera image about noon Tuesday on U.S. 50 at Kent Narrows, east of the Bay Bridge.

The three-lane westbound span had been closed for routine overnight sandblasting and painting work, as it has been for the past month or so, authority officials said. However, after workers noticed the unusual movement just after midnight, they left the bridge for their safety, officials said, and the span remained closed.

Workers were evacuated as a precaution, Bartlett said, particularly because many were perched on scaffolding.

Bartlett said the bridge was last inspected in March.