[4] Maintaining a straight north-westward course, it passes beneath Courtney Park Drive and Derry Road, with a slight jog to the right between the two underpasses.

Until it was decommissioned across the Greater Toronto Area, Highway 7 was concurrent between Queen Street East and Bovaird Drive.

[5] As it passes beneath Mayfield Road, the highway makes a sharp turn to the west and descends through the Etobicoke Creek valley.

The central concrete median barrier and high-mast lighting end as the freeway's opposing carriageways merge, becoming Highway 10 which continues north to Orangeville, Shelburne and eventually Owen Sound.

[9][10] Successor Jim Archdekin announced in the new year that he would meet with highways minister George Gomme to discuss the route of the bypass.

[12] Ontario Premier Bill Davis, who was known as "Brampton Billy", formally initiated the construction of Highway 410 along the Heart Lake Road corridor during his administration.

This portion was renamed Tomken Road (as a continuation of a street linked to its southern terminus when a jog was eliminated), and a diversion was constructed by the City of Brampton to connect it with Steeles further east.

Construction to twin the highway began in 1983, following the completion of a culvert over the east branch of the Etobicoke Creek;[17] the interchange with Clark Boulevard was built at the same time.

[26] As completed to its initial terminus in mid-1991, Highway 410 ended just north of the interchange with Bovaird Drive, as the opposing carriageways merged under the western span of the Bovaird Drive overpass (although separated by a Jersey barrier for some distance) and after an S-curve the freeway transitioned to an arterial street and continued north as Heart Lake Road.

[29] Planning for the 8.5-kilometre (5.3 mi) freeway began with the submitting of an Environmental Assessment by the Ministry of Transportation of Ontario (MTO) in October 1995.

The new section, planned and built as a four lane freeway, was constructed on a new alignment in order to bypass the Heart Lake Conservation Area.

[32] Premier of Ontario Ernie Eves officially announced the extension on June 23, 2003; construction subsequently began on the first phase.

Upon its opening, trucks were prohibited from driving along it due to concerns of them travelling on the two lane Mayfield Road; this ban has since been lifted.

This resulted in Hurontario Street becoming discontinuous as it was split into two segments, with the northern end of the southern portion realigned so it defaults to Valleywood Boulevard (which leads to a new residential community), with a new interchange connecting to the freeway extension that soon transitions into the northern portion of Hurontario Street (which also assumes the provincial Highway 10 designation) as it crosses into Caledon.

A C$156.7 million contract was awarded to Aecon Construction to expand the freeway by adding one general purpose and one High-occupancy vehicle (HOV) lane in each direction.

The overpass is being widened, ramps are being added to provide access to and from the section of Highway 410 north of that junction, and a short southbound collector lane is being implemented between Derry Road and Courtneypark Drive due to the close proximity of these interchanges.