The Chesapeake Bay Bridge will soon be better protected from ship strikes like the one that collapsed the Key Bridge, the Maryland Transportation Authority wrote Monday in response to a scalding report from federal regulators.

Officials said they have completed a new risk analysis of the Bay Bridge one month after the National Transportation Safety Board admonished the authority for failing to assess its most essential bridges for the threat of vessel collisions.

Maryland informed the NTSB it will add physical fortifications to the integral crossing connecting Annapolis and the Eastern Shore after conducting the risk analysis.

A similar study could have prevented the Key Bridge collapse, the NTSB said in a scathing report and accompanying news conference in March, one year after a cargo ship lost power and decimated the structure, killing six construction workers.

In its measured reply, Maryland told the NTSB that it has completed the $600,000 analysis of the Bay Bridge and expects the budget for new physical protections to be $160 million, which could include robust pier fenders and artificial islands known as dolphins.

The authority had previously indicated preliminary plans to build pier protection, but Monday’s letter formalized the project. The NTSB had required the authority to reply to it within 30 days of last month’s rebuke.

An NTSB analysis found that the Key Bridge, built in the 1970s, was 30 times more susceptible to ship strikes than the the federal bridge code allows for newly built bridges. Maryland’s new analysis of the two spans of the Bay Bridge — which were built in the 1950s and 1970s — found that it, similarly, does not meet the vessel collision criteria required of new bridges.

It did not share how much more susceptible the bridge is to ship strikes than the modern standard.

Last spring, the authority initiated a project to study Bay Bridge fortification — something it was “not obligated to do” by law, it stressed.

“Bridges that comply with their federal permit throughout the United States do not require modification,” the authority said in a news release Monday. “That is true for the Bay Bridge.”

NTSB Chair Jennifer Homendy criticized the authority in a March 20 press conference for never assessing the Key Bridge for the possibility of ship strikes.

Since a vessel knocked down Florida’s Sunshine Skyway in 1980, there have been several federal recommendations, by various entities, that bridges be studied for ship strike. But, as the NTSB’s report noted, bridges such as the Key Bridge were never required to be analyzed.

The NTSB identified 72 bridges “over navigable waterways frequented by ocean-going vessels” that were built decades ago, before the threat of ship strikes was fully contemplated by the federal bridge code. Of those, the NTSB found that the vast majority, 68, had never been assessed.

Even today, there is no federal decree that those potentially vulnerable bridges be studied for ship strikes, despite many near misses. The NTSB has urged owners to assess their bridges, but does not have the power to mandate them.

Homendy’s comments last month were her strongest yet concerning bridge security in the aftermath of the Key Bridge collapse. Asked if drivers should reconsider driving across the Bay Bridge, Homendy said they “have to make their own decisions.”

The following week, Maryland Transportation Authority Executive Director Bruce Gartner countered, expressing his confidence in the bridge.

“I would also like to assure you that our facilities, including the Bay Bridge, are safe to travel,” he said during a late March authority board meeting.

Neither of the Bay Bridge’s spans has been struck by a large vessel, but the risk — infinitesimal, but real — remains. A ship experienced a steering issue near the Bay Bridge last year, prompting the first closure of the bridge in recent memory.

Last year, the authority contracted engineering firm Moffat & Nichol, a leader in ship strike analysis, to study the possibility of vessel collisions at the Bay Bridge. Essentially a complex mathematical equation, a ship strike analysis considers a multitude of variables such as ship traffic and the proximity of the shipping channel to piers.

The NTSB criticized the authority in March for not having completed the analysis as of October, although the NTSB did not note whether it had sought an update since then. The assessment was ongoing at that point.

Since the early 1990s, new bridges built in the U.S. are required to meet certain specifications regarding vessel collisions.

A Johns Hopkins survey recently found that many aging bridges across the country are susceptible to vessel collisions. The worst offender, in Louisiana, can expect to be hit once every 17 years. The fallen Key Bridge was likely to be hit once every 48 years and the Bay Bridge could expect to be hit once every 86 years, researchers found.

The transportation authority told the NTSB in its letter that it is “developing a comprehensive risk reduction plan” at the Bay Bridge and listed short-term strategies, including reducing vessel speeds and one-way transits. It also included long-term strategies, such as physical fortifications, but did not include a timeline for implementation.

Last year, the authority shared a preliminary plan for $145 million in Bay Bridge protections with an expected completion date of winter 2027-2028. Given the current status of the project — design will begin this summer — completion of Bay Bridge fortifications would appear to be at least a few years away.

The authority must also consider a potential Bay Bridge replacement in the coming decades. It is possible that physical protections added near the current Bay Bridge could be integrated into fortifications of a future structure, Jim Harkness, the authority’s chief engineer, said at last month’s board meeting.