You'll want to avoid a bunch of roads on Sunday due to the Boston Athletic Association Half Marathon making its way through the Emerald Necklace park system. An estimated 9,000 runners will start the 13.1-mile course at 8 am from White Stadium in Franklin Park, where the race ends, too. Roads along the route will be closed from 7:30 am to approximately 11 am. The race starts on Pierpont Road. The course heads out from Franklin Park, along New Washington Street and Forest Hills Drive, past the Arnold Arboretum, Jamaica Pond and the Arborway/Jamaicaway.