Matt Cullen is leading Detroit's latest transit initiative, the privately-funding M-1 line along Woodward Avenue. Smart City talked to Matt about the impact he believes light rail can have on the city's redevelopment ambitions and why investing in Detroit now makes sense. Matt is President and Chief Operating Officer of Rock Enterprises in Detroit, the portfolio of companies owned by Quicken Loans founder's Dan Gilbert. Matt is also in charge of Gilbert's "Detroit 2.0" development initiatives in downtown Detroit, which includes spearheading Quicken Loans' Detroit headquarters project and move downtown.Matt is a 29-year veteran of GM, where he was General…