Carolyn Flowers, most recently acting administrator of the U.S. Transportation Dept.'s Federal Transit Administration, has joined AECOM as senior vice president and national transit practice leader.

She also had been CEO and director of public transit for the Charlotte Area Transit System, responsible for countywide bus and rail transit planning and management, and before that, chief operations officer for the Los Angeles County Metropolitan Transportation Authority.

Flowers also co-chaired the American Public Transportation Association’s Reauthorization Task Force.

"Carolyn brings a breadth of understanding and experience to this position that will provide our clients with industry-leading insight into the challenges facing public transportation,” said Fred Werner, president of design and consulting services for AECOM.

Huitt-Zollars Inc., a Dallas engineer-architect, has elevated Robert J. McDermott to president. He succeeds firm co-founder Robert L. Zollars, who will remain chairman. McDermott is formerly executive vice president.

The Institute for Sustainable Infrastructure (ISI), Washington, D.C., has named John M. Stanton as president and CEO. He succeeds Bill Bertera, who was first to hold those roles when the non-profit infrastructure sustainability education and research group was launched in 2012. Stanton had been executive vice president and regulatory counsel for Solarcity in San Mateo, Calif., which ISI says is the nation’s largest solar energy company. He also served as executive vice president and general counsel of the Solar Energy Industries Association, where he oversaw legal and government affais. ISI was founded by the American Public Works Association, the American Society of Civil Engineers, and the American Council of Engineering Companies to promote sustainable infrastructure through a web-based project rating tool called Envision that was developed in partnership with the Zofnass Program for Sustainable Infrastructure at Harvard University.

Joseph Aiello will join New York City--based Broadway Construction Group as a partner and chief operating officer, following the building construction management firm’s Jan. 18-announced link with Zephyr Construction Management, of which he was founder and principal. Broadway was founded in 2013.

U.K-based engineering consultant Mott MacDonald has elevated executive board director Mike Haigh to global managing director. With the firm since 1981, he had been managing director of the Europe and Africa region.  Mott MacDonald ranks at No. 17 on ENR’s list of the Top 150 Global Design Firms with $2.3 billion in 2015 global revenue and 16,000 employees.

Robert J. Slimp has been named chairman, president and CEO of HNTB Holdings Ltd. Harvey Hammond has become executive chairman, according to Bloomberg. Slimp, who joined the firm in 2005, continues as CEO of its unit HNTB Corp., a post he has held since 2013. HNTB ranks at No. 21 on ENR's list of the Top 500 Design Firms, with $915 million in 2015 revenue.

Elizabeth “Ibba” Surface is promoted to president of Nashville structural engineer Ross Bryan Associates. She had been treasurer and principal of the 26-person firm, and succeeds Don Yarbrough who remains as a board member and senior principal.

Rosser International Inc., the Atlanta architect-engineer, has elected 33-year veteran Raymond C. Ashe as CEO. He was director of architecture.

Steve Stockton, former director of the U.S. Army Corps of Engineers civil works program, has joined Washington, D.C., consultant Dawson Associates as a senior advisor.

Skanska USA Commercial Development has promoted Matt Damborsky to executive vice president in Houston. He was previously a managing director at real estate developer Hines.