Participants in Sunday’s Ironman race will traverse more than 70 miles by swimming, biking and running their way through Raleigh and Wake and Chatham counties. More than 3,100 participants are expected, officials say, with about half of those coming from out of state. The event starts at 7 a.m. with a 1.2-mile swim at Jordan Lake. A 56-mile bike ride through Chatham and Wake counties is next. The final leg is a 13.1-mile run through West Raleigh and downtown Raleigh. Vehicles will be rerouted on parts of Dawson Street, Wilmington Street, Edenton Street, McDowell Street, Lake Wheeler Road and Tryon Road during the day.