"In order to put these in, we want to make sure we've done the right due diligence as far as the community's concerned and the intersections are concerned," Tunney said. "Because the data seems to be conflicting at times, based on some of the Tribune analysis. So we want to make sure there's a thorough study, make sure it's before they're put in, and not done afterward. And then we also want to make sure the alderman has control over their intersections, because it's our constituents that we have to respond to."