Nine Senate Democrats sent an urgent letter Wednesday imploring the nation’s top auto safety regulator to “accelerate the implementation” of several potentially lifesaving vehicle safety measures called for in the 2021 Infrastructure Investment and Jobs Act, commonly referred to as the bipartisan infrastructure bill. 

Among the outstanding provisions was an order from Congress that the National Highway Traffic Safety Administration draft a new standard for the strength of vehicle seats — a measure prompted by a long-running CBS News investigation.

“The agency must still finalize some of its proposed rules and has not yet issued rules for many provisions — rules that are already overdue or nearing their statutory deadline,” the senators wrote in the letter.

Sens. Ed Markey, Richard Blumenthal, Ben Ray Lujan, Elizabeth Warren, Amy Klobuchar, Dick Durbin, Jack Reed, Ron Wyden and Chris Van Hollen sent the letter to NHTSA Deputy Administrator Sophie Shulman asking for response by Dec 15. 

The NHTSA does not currently have an administrator to head the agency, a post that has been vacant for most of the last two administrations.

Since 2015, CBS News reports have brought to light longstanding concerns over seatback safety and exposed dire weaknesses within the federal standard, which was created in 1967. The probe found that front seats in vehicles were vulnerable to collapsing in crashes in which those vehicles had been rear-ended, even though the seat construction adhered to national requirements.

NHTSA was given two years to develop new safety standards for seat strength, primarily in an effort to protect children sitting in the back seats of vehicles. Fatal incidents in which front seats collapsed backward in rear-end accidents, and onto kids seated behind them, had already been on the rise for years. 

NHTSA missed the deadline, but in July, it announced its plans to potentially update that safety standard. While it sought public comments, the agency has not announced further action.

“It’s unacceptable that backseat passengers – especially children – are still at risk of being killed by a collapsing front seat during a crash,” Markey said in a statement. “After Senator Blumenthal and I passed our Modernizing Seatback Safety Act, and doggedly urged NHTSA to act, I was glad the agency finally issued its proposed rule updating seatback safety standards. But our work is not done yet, and NHTSA must quickly finalize this rule and save lives.”

Other outstanding safety provisions the senators are seeking status reports on include an annual recall completion list, automatic shutoff for vehicles with keyless ignition systems, setting minimum standards for crash avoidance systems, distracted driver reduction research, updates to hood and bumper standards, a study of existing reporting requirements for vehicle manufacturers regarding potential safety issues, requirements for new vehicles to be equipped with advanced impaired driving prevention technology and a requirement aimed at reducing the likelihood a child is left in a hot car by equipping new vehicles with a system to alert the driver to check rear seats.