DETROIT — Police in Windsor, Canada, on Tuesday intercepted a convoy of at least a half-dozen trucks suspected of heading back to the Ambassador Bridge just days after it reopened, Mayor Drew Dilkens said. The mayor noted the convoy during a Wednesday afternoon briefing in which he sought to reassure small businesses and neighbors located or traveling near the approach of the bridge that the remaining barriers left in place after a nearly weeklong blockade are still necessary. A return to normal traffic flow is “not yet possible,” he said. Windsor Police Chief Pamela Mizuno noted Wednesday tha…