[note 1] The highway once extended even farther to the Quebec boundary in East Hawkesbury with a peak length of about 2,180 km (1,350 mi).

Through July and August 1920, a highway east of Ottawa to Pointe-Fortune at the Quebec boundary, known as the Montreal Road, was assumed by the department.

[2][3][4][5] A portion of this original highway was lost when the completion of the Carillon Generating Station in 1964 raised the water level of the Ottawa River north of Voyageur Provincial Park.

Following World War I, discussions of a cross-continental road through Canada became vocal and construction of such a route was underway in several places.

[12] By June 1931, planning for the route of the highway was complete,[13] and work underway on the new link between Thunder Bay and Winnipeg that would roughly parallel the Canadian Pacific Railway.

A convoy of vehicles travelled from Thunder Bay to Winnipeg along the route, resting overnight in Kenora before completing the two-day journey.

[18] The men, with public support behind them, headed north to highway camps, where mounting tensions due to low wages, poor conditions, lacklustre food, isolation, and military-like discipline resulted in organized labour strikes.

[20] Before the outbreak of World War II in 1939, a new bridge spanning the Nipigon River was completed alongside a 91.6 km (56.9 mi) highway eastward to Schreiber.

The Greber Plan was produced by Jacques Gréber under the direction of Prime Minister William Lyon Mackenzie King in the late 1940s.

[25] The plan called for the complete reorganization of Ottawa's road and rail network, and included amongst the numerous parkways was an east to west expressway along what was then a Canadian National Railway line.

[26][27] With the rail lines removed, construction of the new expressway got underway in 1957 when Queen Elizabeth visited Ottawa to open the first session of the 23rd Parliament.

On October 15, the Queen detonated dynamite charges from the Hurdman Bridge, which now overlooks the highway as it crosses the Rideau River, and formally dedicated the new project as the Queensway.

At the ceremony, premier Leslie Frost indicated that the entire project would cost C$31 million and emphasized the importance of the link to the Trans-Canada Highway.

In addition to bypasses around almost every urban centre it encountered, many original sections have been downloaded to regional and local jurisdiction or decommissioned entirely to lie abandoned in the forest.

Marie—however this plan has long been stalled by the MTO and provincial government, largely due to the high cost of construction and uncertain demand; there has also been no environmental impact assessment to date.

[55] Construction to twin the Arnprior Bypass portion of Highway 17, which included a new interchange at White Lake Road, began during the spring of 2009.

It meets the northern terminus of Highway 71, then makes a gradual eastward journey through the lake-dotted Kenora District to the town of Dryden.

Along with the railway crossing immediately to the south, and another on the northern shore of Lake Nipigon, this forms the narrowest bottleneck in Canada between the Atlantic and Pacific oceans.

It meets the western terminus of Highway 101 near Wawa, which provides for a shorter route to Sudbury via the Sultan Industrial Road.

Shortly thereafter, it turns to the east and travels along the North Channel of Lake Huron towards Sudbury, passing through numerous small towns, including Thessalon, Blind River, Massey and McKerrow.

At Sudbury, the highway widens into a freeway through the Walden area of the city until reaching the Southwest / Southeast Bypass at Lively, where it narrows again to a Super 2 road.

Here it turns east and travels through the city's outlying neighbourhoods of Coniston and Wahnapitae; a new freeway alignment of this route is currently in the planning stages.

The highway route passes through the rural municipalities of Markstay-Warren and West Nipissing before reaching North Bay, where it follows an undivided four-lane expressway alignment, with reduced but not full control of access, through the city of North Bay; as of 2012, early preparations have taken place for a freeway conversion and realignment of this segment.

Marie MPP David Orazietti has spearheaded a petition to have the entire highway four-laned from Arnprior to Sault Ste.

Within the township of Whitewater Region, however, a new alignment is planned several kilometres east of the existing road in order to bypass communities such as Cobden.

[64] In August 2017, the Ministry of Transportation formally confirmed that detail design studies have commenced on the next westward extension of Highway 417, from the existing terminus at Scheel Drive in Arnprior to three kilometres west of the Bruce Street intersection at Renfrew.

[67] Studies commenced on an extension of the four-lane route easterly to Bonfield in early 2011,[68] and from Eau Claire Station to the Nipissing District-Renfrew County boundary in early 2012; further studies on the routes from Bonfield to Eau Claire Station and from North Bay to Cache Bay are expected to begin at a later date.

[71] Preliminary route planning studies have also been completed on the freeway's westerly extension to McKerrow, near Espanola, but no construction schedule has been announced to date.

Marie, the expressway segment currently ends six kilometres short of its eventual terminus at Black Road and Second Line, as an agreement has yet to be reached with the Batchawana First Nation regarding land use through Rankin.

[73] In February 2011, the Ministry of Transportation announced that the expressway's current level intersection at Highway 638 in Echo Bay will be converted to a full interchange.