In Doraville, Ga., the developer of Assembly Yards, a mixed-use residential, office and retail project, is choosing between three autonomous vehicle companies to operate a driverless shuttle in the 165-acre project, which had been the site of a former General Motors plant. "We want our development to push the boundaries of new transit solutions," said Matt Samuelson, chief operating officer of Integral Group LLC, the developer of Assembly Yards. In the real-estate industry, interest in driverless vehicles is being fueled by a simple fact: Success in developments often hinges on the density of a project. Developers and property owners are angling to host autonomous vehicle trial programs in hopes that their rollout will lead people to rely on driverless ride-hailing options like Uber and Lyft rather than owning private vehicles--freeing up space for homes, offices and other uses that produce more income than parking spaces. In traditional retail real-estate projects, five parking spaces are needed for every 1,000 square feet of built floor area.