Lawmakers added a car safety provision to the infrastructure bill. But some say it still isn't enough.

Following a six-year CBS News investigation that revealed potential safety dangers in vehicle seats, legislation aimed at increasing the federal strength standard has been included in the $1 trillion bipartisan infrastructure bill. But its congressional backers say the proposed legislation needs to be stronger.

In a series of stories that began airing in 2015, CBS News revealed that when hit from behind, car front seats may collapse backwards and their occupants can be propelled – forcefully – into the rear seats where children usually sit. Now, the proposed 2,702-page infrastructure bill includes two paragraphs that, if passed, would instruct the National Highway Traffic Safety Administration to draft a new regulation within two years that updates the decades-old standard for the strength of vehicle front seats. The secretary of transportation would then decide if it should be implemented and "establish a date for required compliance with the final rule not later than 2 motor vehicle model years after the model year during which the effective date of the rule occurs."