History of King's Highway 43B:
King's Highway 43B was a short business route that was created in 1958 when a new alignment of Highway 43 was built to bypass two at-grade railway crossings on the western approach to Chesterville. The Highway 43B business loop followed the former route of Highway 43 into Chesterville via Loucks Road (today's Stormont, Dundas & Glengarry Road 9) and Chesterville's Main Street North. Jurisdiction over a 1 km section of Highway 43B along Main Street North within the Village of Chesterville was transferred from the Department of Highways of Ontario (DHO) to the municipality, effective December 20, 1962. This transferred section of Highway 43B began at the intersection of Main Street North and Queen Street and extended north along Main Street North to the northern limits of the Village of Chesterville at Loucks Road. The remaining 2 km section of Highway 43B via Loucks Road from the west junction of Highway 43 to the northern limits of the Village of Chesterville was transferred to the County of Dundas, effective September 20, 1969. Highway 43B was also known by a 7000-Series Highway number (Highway 7024). In 1973, a new bypass was completed around the southern side of Chesterville, which included a new bridge over the South Nation River. Highway 43 was rerouted along the new Chesterville Bypass upon its completion. It is believed that the old route of Highway 43 along Main Street South and Queen Street briefly became Highway 43B once again in 1973, but this has not yet been confirmed. Jurisdiction over the last provincially-owned section of Old Highway 43 from the new Chesterville Bypass to the southern limits of the Village of Chesterville at South Street was transferred to Dundas County, effective September 22, 1976.