Highway 88 began at an intersection with what was then Highway 27, but is now known as Simcoe County Road 27, in the community of Bond Head. It proceeded eastward into farmland, where it intersected 5th Sideroad just prior to encountering an interchange with Highway 400 at Exit 64. At the northwest corner of the interchange was Yogi Bear's Jellystone Park and Camp Resort. East of Highway 400, the highway continued through farmland, intersecting 10th Sideroad;^[1][2][3] the ghost community of Middleton (sometimes spelt Middletown) formerly existed at this crossroad.^[4][5] It entered the urban area of Bradford at what is now Professor Day Drive, before ending at an intersection with former Highway 11. The roadway continued through this intersection as Highway 11 (Holland Street East), turning southeast towards Newmarket and Toronto; Highway 11 continued northwards to Barrie along Barrie Street.^[1][2][3]

The road that would become Highway 88 was originally built after an act to build and maintain the 7th concession of West Gwillimbury as a toll road was passed on April 20, 1836. The toll road connected Bond Head with Holland Landing and featured two toll booths: one at Middleton and the second on the south side of the Holland River. In the spring of 1851, planking of what was then known as the West Gwillimbury Road began under a funding agreement with the government of Upper Canada.^[6][7] It was completed in October, featuring 3-inch thick planks laid on stringers, and was wide enough for a wagon; the first "paved" road in Simcoe County. Loaded wagons had the right-of-way, and the well-established farmland around Bond Head led to it becoming a major transport route to markets in Toronto.^[8] Although initially profitable, the deteriorating condition of the planks, frequent upkeep, and payments to those injured by the condition of the road led to it costing money by 1857. Consequently, in October 1858, Simcoe County council repealed the act that established the plank road, and instructed the county surveyor to remove the planks and level the road.^[9]

The portion of the plank road between Bradford and Holland Landing followed what is now Bridge Street along the south side of the Ontario, Simcoe and Huron Railway (opened June 15, 1853,^[8] now the CNR and GO Transit Barrie line) across the Holland River, then crossed to the north side of the tracks, following what is still today known as Toll Road.^{[10][5][11][12]} A part of this, from Barrie Street in Bradford to the south side of the Holland River, was incorporated into Highway 11 on August 18, 1920.^[13] Highway 88 would be established nearly 18 years later, when the remainder of the former plank road between Bradford and Bond Head became a provincial highway on April 13, 1938.^[14] While still a dirt road, it was improved to a gravel surface the following year.^[15]

Planning for a new "superhighway" between Toronto and south of Barrie was carried out between 1944 and 1947,^[16][17] with construction beginning later that year.^[18] When Highway 400 fully opened to traffic on July 1, 1952,^[19] a cloverleaf interchange with Highway 88 was included. It was one of the last remaining in Ontario when the loops were removed in 2011, converting it to a diamond interchange.^{[citation needed]} Highway 88 was paved in its entirety in 1956.^[20][21]

As part of a series of budget cuts initiated by premier Mike Harris under his Common Sense Revolution platform in 1995, numerous highways deemed to no longer be of significance to the provincial network were decommissioned and responsibility for the routes transferred to a lower level of government, a process referred to as downloading. Highway 88 was downloaded entirely on January 1, 1998, and transferred to Simcoe County, which designated it as County Road 88.^[2][22]

The following table lists the major junctions along Highway 88, as noted by the Ministry of Transportation of Ontario.^[1] The entire route was located in Simcoe County.^[3] 

• Ellis, Bernice Merrick (1984). Life on the Old Plank Road: Highway 88. Tecumseth and West Gwillimbury Historical Society. ISBN 0-9691367-2-2. Retrieved September 22, 2021.
• Shragge, John; Bagnato, Sharon (1984). Footpaths to freeways : the story of Ontario's roads : Ontario's bicentennial, 1784–1984. Toronto: Ontario Ministry of Transportation and Communications, Historical Committee. ISBN 9780774393881. OCLC 12554626.