History of Secondary Highway 531:
Secondary Highway 531 is a local highway in the District of Nipissing that provides access from Highway 17 east of North Bay to the Town of Bonfield. The Bonfield Spur Highway was designated as Highway 531 by an Order-in-Council dated May 9, 1956, and was first depicted on a Preliminary Route Plan prepared by the Department of Highways of Ontario (DHO) in May, 1956. Highway 531 was already paved at the time of designation in 1956, and has changed very little since it was first established. Unless posted otherwise, the speed limit on Highway 531 is 80 km/h (50 mph). Services are no longer available on Highway 531, as the highway's only gas station at the Highway 17 Junction has been closed.