WASHINGTON — Thousands of car owners who Tuesday were urged to check a government website to see if their air bags are safe have overwhelmed the site and U.S. regulators say it might take several days before the database is fully accessible.

For some people who were able to get though, complete vehicle-identification number information related to the recall of a record 34 million cars wasn’t available, and won’t be for several days, according to the National Highway Traffic Safety Administration. Traffic on the website on Tuesday night was 44 times normal, the agency said.

“We’re working with the automakers to provide that information as quickly as possible,” a NHTSA spokesman, Gordon Trowbridge, said in an e-mail. He urged people to be patient.

Auto-parts maker Takata agreed Tuesday to double the number of vehicles covered by a recall to fix potentially faulty air bags that can shoot shrapnel at drivers and front-seat passengers. Regulators said it is the largest automotive recall in U.S. history.

After the midday announcement, traffic on NHTSA’s vehicle- identification number page surged to 440,000 searches, up from what was typically about 10,000 per day last week, according to preliminary information from NHTSA.

The previous record in a single day was 110,000 searches, the agency said.

This is at least the second time in seven months that the agency suffered a website meltdown. In October, shortly after Honda expanded a related air-bag recall for 8 million vehicles, the search function was inoperable for days as the regulator sorted through software changes rolled out right before the announcement.

The agency said it took steps to bolster the website, including moving other functions to separate servers ahead of the Tuesday announcement. The preparation allowed it to handle “traffic far in excess of even our busiest previous daily record,” Trowbridge said.