Sen. Sherrod Brown called on the U.S. Department of Transportation to “stop dragging its feet” on implementing 2012 legislation to improve bus safety following a January crash that killed five people, including an Ohio State University graduate.

Brown and Georgia Sen. John Lewis, a fellow Democrat, sent a letter to Transportation Sec. Elaine Chao on Wednesday urging it to adopt standards in that law that so far have gone unaddressed.

The department issued a rule in 2013 to require seat belts on new motor coaches, but not on older buses, according to the letter. The senators wrote “we have long been concerned” about excluding older vehicles.

The bus that crashed in Pennsylvania in January en route to Columbus did not have seat belts, according to the letter. Five people were killed in that crash, including Eileen Zelis Aria, 35, an Ohio State University College of Dentistry student who was traveling from New York City to Columbus to shadow dental anesthesiologists and see friends.

The Z&D Tour Inc. bus held 56 passengers when it crashed into a concrete median before rolling onto its side on the Pennsylvania Turnpike, about 30 miles east of Pittsburgh, around 3:30 a.m. Jan. 5.

Brown and Lewis also called for the department to issue rules on roof strength, measures to prevent ejection and rollover crash avoidance.

“Passengers should not have to roll the dice on whether the bus they take to travel across the United States is new enough to have life-saving equipment — all commercial motorcoaches should be equipped with seat belts,” the senators wrote.

In an email, a National Highway Traffic Safety Administration spokesperson wrote: “To date, NHTSA has completed many of the mandated rulemakings from (the legislation) and all the remaining mandated rulemakings have been initiated and are in varying stages of completeness.”

Brown said during a conference call with reporters that he was “not qualified” to say whether portions of the 2012 law that have not been implemented could have saved lives in the crash.

“I want to make sure it’s fully implemented so that other people’s lives would be saved,” he said.

John Betts, whose son, David, was among the members of the Bluffton University baseball team killed in a bus crash in Georgia in 2007 advocated for the changes in the 2012 legislation. He said regulators not fully adopting it is “a promise only partially kept.”

“Let’s stop messing around with the vulnerable public lives,” he said during the conference call.

Brown also chastised Senate leadership over its handling of the impeachment trial of President Donald Trump. Sen. Mitch McConnell has pushed the proceedings late into the night and restricted media access to prevent the public from watching, he said.

Brown and other Democrats want to call additional witnesses in the trial, but Senate Republicans in the majority have put off a vote until after House managers and Trump’s defense make their case.

“Sen. McConnell is rigging the system,” he said.