Ontario Highway 123 (#1) History - The King's Highways of Ontario

King's Highway 123 was a short highway which served as an eastern entrance route into St. Thomas, via Wellington Street, Fairview Avenue and Sinclair Avenue. Highway 123 connected to Highway 3 between the Michigan Central Railway crossing and Centennial Road in Yarmouth Township, immediately east of St. Thomas. The highway's western terminus was at the St. Thomas City Limits, which at that time was located where First Avenue exists today.

Although the route of Highway 123 first appeared on the 1955 Official Ontario Road Map, the highway was actually acquired by the Department of Highways of Ontario (DHO) back in the mid-1930s. On May 22, 1934, a Preliminary Route Plan was prepared by the DHO, which showed the proposed route of a new King's Highway at the eastern entrance to St. Thomas. The proposed highway followed Construction Road (today's Sinclair Avenue), Council Road (today's Fairview Avenue) and Wellington Street. The highway was paved by the DHO immediately after assumption in 1934. The new highway was officially assumed into the Ontario Highway system on June 1, 1934, although the King's Highway 123 designation was apparently not assigned to the route until 1955. It is not certain what route number, if any, was assigned to this short highway prior to the assignment of the Highway 123 designation in 1955. The highway was decommissioned on April 15, 1957, when Highway 123 was transferred from the province to the Township of Yarmouth. A different, unrelated Highway 123 existed in North Bay between 1960 and 1979.