The Department of Transportation (DOT) has named T.F. Scott Darling III, chief counsel of the Federal Motor Carrier Safety Administration (FMCSA), as acting administrator to succeed Anne S. Ferro, whose term as administrator ended Friday.

In a related development, FMCSA Deputy Administrator Bill Bronrott will leave the agency by the end of the year, Ferro said in a letter to employees. Bronrott has spent more than four years at DOT. No replacement has been named.

President Obama appointed as Darling FMCSA chief counsel in September 2012. He came to the agency from the Massachusetts Bay Transportation Authority, the public transit agency serving the greater Boston area, where he served as the deputy chief of staff and assistant general counsel.

Ferro will become president and CEO of the American Association of Motor Vehicle Administrators (AAMVA). AAMVA members are responsible for the issuance of commercial drivers licenses (CDLs). The organization also provides best-practice guidelines, training programs, and operational guidance to support those efforts.

AAMVA also runs the Commercial Driver's License Information System (CDLIS) that enables states to ensure that each commercial driver has only one license and one complete driver record.