The southbound drive on Route 15 through Jefferson is back to normal, six weeks after a 124-year-old Morris County bridge was closed due to structural concerns. A temporary bridge opened Sunday, five days ahead of schedule, officials said. Thousands of cars had been detoured onto local streets starting June 4, when the emergency shutdown of the bridge began. Other motorists sought out different highways, including Route 23, for traveling further south or east. “Our community appreciates that the project was completed a week earlier than anticipated,” Jefferson Mayor Eric Wilsusen said. “This e…