History of King's Highway 7B (Thornhill):
The Thornhill Business Route was created when Highway 7 was relocated onto a new bypass around Thornhill in September, 1963. The new Thornhill Bypass followed a section of Langstaff Road and Bathurst Street around the northern and western sides of Thornhill. The old alignment of Highway 7 through Thornhill became Highway 7B. The route of Highway 7B started at the intersection of Centre Street and Bathurst Street (part of the Thornhill Bypass). The route of Highway 7B headed east from Bathurst Street via Centre Street to Yonge Street. At Yonge Street, Highway 7B turned north concurrently with Highway 11. At Langstaff Road, Highway 7B ended at the Highway 7 Junction. Originally, the route of Highway 7B was 4.2 km in length. However, during the early 1970s, the route of Highway 7B was shortened. Rather than return to Highway 7 at Langstaff via Yonge Street, the highway was truncated at its junction with Highway 11 in Downtown Thornhill. This change apparently took place in 1973. In the mid-1980s, a new route for Highway 7 was constructed between Bathurst Street and Concord. This relocated section of Highway 7 bypassed an even greater portion of Centre Street. As a result, the route of Highway 7B had become discontinuous from the relocated route of Highway 7. It was therefore decided that the Thornhill Business Route was no longer required in the King's Highway System. The entire route of Highway 7B from Bathurst Street (Highway 7) to Yonge Street (Highway 11) was transferred to the Town of Vaughan, effective July 25, 1985.