The Maryland Transportation Authority is considering installing protective barriers at the Bay Bridge in the wake of the collapse of the Francis Scott Key Bridge after it was struck in late March by a large container ship.

Here are some key facts about what the state’s done and is doing:

The Maryland Transportation Authority never upgraded the pier protection system at the Key Bridge, which dated to 1977, and was designed when ships were far smaller.

Members of the Association of Maryland Pilots raised concerns about potentially dangerous ship strikes at Maryland bridges several times in the 2000s at meetings of the Baltimore Harbor Coordination Committee, a cross-section of government agencies and maritime groups. It’s unclear whether transportation authority members were at the meetings.

When the Key Bridge was inspected in May 2021, its pier protection system was rated as “functioning,” but only by 1977 criteria. Bridge inspectors don’t use the standards set by the Guide Specification and Commentary for Vessel Collision Design of Highway Bridges, a document issued by the Federal Highway Administration in 1991, when assessing older bridges.

Measures were taken to reinforce the Key Bridge and the Bay Bridge in recent decades, but they focused on possible terror threats, not cargo ships, a former Maryland transportation secretary said.

Asked whether it had ever considered upgrading pier protections at the Key Bridge, the transportation authority responded with a statement: “Experts constantly evaluate the likelihood of catastrophic events versus realistic mitigation efforts. … The MDTA is unable to release sensitive security information the disclosure of which would reveal vulnerabilities of critical Maryland bridges and compromise the safety of the structures and the public.”

The transportation authority, which never installed protective barriers at the Bay Bridge, is now studying that possibility. A spokesman said the agency hopes to be “underway with long-term improvements” by the end of the year.