After graduating college, Margro worked as a rocket scientist for a year, working as a defense contractor on the Minuteman missile guidance system. In 1972, Margro joined the Southeastern Pennsylvania Transportation Authority in Philadelphia as the only electrical engineer in a team tasked with maintaining an aging and ill-maintained transit system acquired from a private company. He worked at SEPTA for 18 years ; his roles there included manager of facilities engineering; senior program manager, electrical facilities; chief engineer; and ultimately assistant general manager of engineering and construction.
First stint at BART (1990 – 1995)
Margro worked at BART from 1990 to 1995 as assistant general manager of transit system development. In that position, he was responsible for the BART Extensions Program, including the Pittsburg/Bay Point extension and the Dublin/Pleasanton extensions. The stations would open between 1995 and 1997.
Break from BART (1995 – 1996)
Margro worked for a year at the New Jersey Turnpike Authority as Director of Maintenance and Engineering Services/Chief Engineer.
Second stint at BART (1996 – 2007)
On June 1, 1996, it was announced that BART General Manager Richard A. White was leaving BART to become general manager of the Washington Metropolitan Area Transit Authority, with July 26 being his last day at BART. Potential successor candidates mentioned at the time of his departure were Deputy General Manager Dorothy Dugger, Jim Gallagher, Larry Williams, and John Haley. On September 30, 1996, Margro became the General Manager of BART, succeeding White. According to BART board member Tom Radulovich who joined the board at about the same time, there was a general feeling at the time that the BART SFO extension was lagging behind, and part of the expectation from Margro was that he would complete the extension. Under Margro, BART successfully opened the extension in 2003. Margro was also at the helm when Measure AA, a proposal to fund BART's Earthquake Safety Program with $980 million from property taxes, was approved by voters in a referendum, and he oversaw the initial implementation of the program. On April 10, 2007, BART announced that Margro was retiring, with June 29, 2007 being his last day of service. Margro would be BART's longest serving General Manager. Board members Radulovich and Lynette Sweet praised his accomplishments, including getting the SFO extension completed, launching the Earthquake Safety Program, and working out a solution with unions representing BART employees to avert financial crisis. Also, it was during Margro's tenure that BART received the American Public Transportation Association's Outstanding Public Transportation System honor in 2004. The praise was echoed by Dan Richard, a former BART board member. On August 23, 2007, Dorothy Dugger, the former Deputy General Manager, who had been filling the role of interim General Manager, became Margro's successor as General Manager.
Margro served as CEO of Transportation Corridor Agencies from 2007 to 2012. TCA operates toll roads in Orange County, California. After a nationwide search for a replacement, TCA hired Neil Peterson as the new CEO, with a start date of June 3, 2013.
