The study on the impact of tearing down Interstate 345 — funded by The Real Estate Council and conducted with the City of Dallas — won't simply be focused on the 1.4-mile stretch of roadway. It'll also examine other roadways corralling Dallas' central business district. And it's not something that will be churned out quickly, said Mayor Mike Rawlings, who spoke to the Dallas Business Journal. "When I met with several business leaders, including The Real Estate Council, the question in the room…