The authority and effectiveness of the National Highway Traffic Safety Administration will be examined during a U.S. Senate subcommittee hearing set for 2:30 p.m. (EDT) on Tuesday, Sept. 16.

Sen. Claire McCaskill (D-Mo.) will chair the hearing, titled “Oversight of and Policy Considerations for the National Highway Traffic Safety Administration.”

McCaskill has been sharply critical of General Motors' slow response to collisions that ultimately led to the ignition switch recalls. Earlier this year, she accused GM of having a "culture of cover-up." The senator has also questioned whether NHTSA has the capability, data and resources to effectively monitor vehicle safety defects.

McCaskill chairs the Subcommittee on Consumer Protection, Product Safety and Insurance, which falls under the Senate Committee on Commerce, Science and Transportation. 

Scheduled witnesses at Tuesday's hearing include David Friedman, NHTSA deputy administrator, and Kendell Poole, chairman of the Governors Highway Safety Administration.

The hearing, set for a live webcast, will also look at implementation of Map-21 legislation.

Click here for a list of hearing witnesses and directions on how to stream the webcast.