A spokesman for Chao did not immediately comment. The White House Office of Management and Budget approved the undisclosed Transportation Department changes to the guidelines on Aug. 31, according a posting on a government website.
On Wednesday, the U.S. House of Representatives will vote on a sweeping proposal to speed deployment of self-driving cars without human controls and bar states from blocking autonomous vehicles. The measure could help many automakers and tech companies keep their pledges of getting self-driving cars on the market by 2020 or 2021.
The House will vote on the bill under fast-track rules that allow no amendments. A bipartisan group of U.S. senators working on similar legislation has not introduced a bill.
The bill, passed unanimously by a House panel in July, would allow automakers to obtain exemptions to deploy up to 25,000 vehicles without meeting existing auto safety standards in the first year. Over three years, the cap would rise to 100,000 vehicles annually.
The House measure would require automakers to provide regulators with safety assessment reports proposed in the 2016 self-driving guidelines, but would not require pre-market approval of advanced vehicle technologies.
Consumer advocates have called for giving the National Highway Traffic Safety Administration quicker access to crash data and more funding to oversee self-driving cars.