A faulty part made by Japan’s Takata has been linked to eight deaths and multiple injuries. It has prompted the largest recall in US history.
Senator John Thune said the size of the Takata recall was causing confusion and delays in replacing the airbags.
The US safety agency said it had set up a dedicated website.
However Mark Rosekind, administrator at the National Highway Traffic Safety Administration (NHTSA), said that the agency was underfunded and did not have enough staff or the right technology.
“You’ve got too many complaints and not enough people,” he said. “It’s just overwhelming.”
He added that the NHTSA had submitted a request for extra funding.
In the US, 34 million cars have been recalled. Globally, the number of vehicles affected is thought to be 53 million.
Questioned on the safety of its airbags today, the Japanese car company said it had changed its design and was no longer using an inflator shaped like a batwing which was involved in the eight fatal accidents.
“We feel very confident in the inflators we are making today,” said Kevin Kennedy, from Takata North America.
“We will continue to do everything we can to ensure uncompromised safety for our customers and the success of the recall efforts,” he added.