Windsor–Tilbury }} The Windsor to Tilbury section of Highway 2A originally was designated in 1929 along the route of what would become
Highway 114, near
Maidstone. When
Highway 18 was redesignated between Windsor and Leamington in 1931, Highway 2 was rerouted onto its former routing. The old routing of Highway 2 prior to that became Highway 2A, and the existing Highway 2A was renumbered as
Highway 3B. Between 1931 and 1938, the route followed the Provincial Highway between Tecumseh Road in downtown Windsor, and Mill Street in Tilbury, both at junctions with Highway 2. In 1938, the entire route was renumbered as
Highway 98 Chatham }} Highway 2A in Chatham was established in 1957 along the original route of Highway 2 when it was rerouted along the West Chatham Bypass (Keil Street) and Grand Avenue. The route began at Highway 2 at the intersection of Richmond Street and Keil Street, following the former into downtown Chatham, where it turned north onto Queen Street then east onto School Street. From there, the route turned north onto Centre Street, which becomes 5th Street shortly thereafter. The route crossed the
Thames River, north of which it became Thames Street and continued to Highway 2 (Grand Avenue East). The route was renumbered as
Highway 2B in 1961 and decommissioned by 1970.
London }} Highway 2A in London provided an alternative parallel route to Highway 2 through the downtown core, travelling from a
concurrent Highway 2 and
Highway 4 eastward along Stanley Street, York Street, Florence Street and finally Highbury Avenue. At its eastern end, it met Highway 2 (Dundas Street). The route was established in 1956 and decommissioned in 1968.
Cornwall }} Highway 2A (Alt.) in Cornwall was a short-lived designation applied along Nine Mile Road (now Power Dam Drive) and Second Street on the west side of the city. It provided an alternate bypass to the
Seaway International Bridge. The route was established in 1965 and remained in place for only two years before being decommissioned in 1967.
Toronto–Newcastle }} As automobile use in southern Ontario grew in the early twentieth century, road design and construction advanced significantly. Following frequent erosion of the former
macadamized Lake Shore Road, a cement road known as the
Toronto–Hamilton Highway was proposed in January 1914. By November 1914, the proposal was approved, and work began quickly to construct the road from Toronto to Hamilton known today as
Lake Shore Boulevard and
Lakeshore Road. The road was formally opened on November 24, 1917, Over the next decade, vehicle usage increased substantially, and by 1920 Lakeshore Road was again highly congested on weekends. In response, the Department of Highways examined improving another road between Toronto and Hamilton. Middle Road, a continuation of Queen Street west of the
Humber River, was chosen to avoid delays on Dundas or Lakeshore. The road was to be more than twice the width of Lakeshore Road at , and would carry two lanes of traffic in either direction. Construction on what was then known as the
Queen Street Extension between
Highway 10 and
Highway 27 began in early 1931, and between Highway 27 and the Humber River on November 1, 1931. Before the highway could be completed,
Thomas McQuesten was appointed the new minister of the Department of Highways, with
Robert Melville Smith as deputy minister, following the
1934 provincial elections. Smith, inspired by the German
Autobahn's—new "dual-lane
divided highways"—modified the design for Ontario roads, and McQuesten ordered that the Middle Road be converted into this new form of highway. A
right-of-way was purchased along the Middle Road and construction began to convert the existing sections to a divided highway, as well as on Canada's first
interchange at Highway 10. When widening in Scarborough reached the
Highland Creek ravine in 1936, east of Morningside, the Department of Highways began construction on a new bridge over the large valley, bypassing the former alignment around the village of
West Hill. From there to Oshawa, the highway was constructed along a new alignment, avoiding construction on the congested Highway 2. As
grading and bridge construction neared completion between Highland Creek and Ritson Road in September 1939,
World War II broke out and gradually money was siphoned from highway construction to the war effort. Despite falling under municipal control, the highway continues to be named Highway 2A. The off ramp from westbound 401 lists Kingston Road with a number 2 regional road marker, despite the fact the road does not have any numerical designation within Toronto. == Exit list ==