Ontario Highway 401

"Highway 401" redirects here. For other uses, see List of highways numbered 401.

Highway 401
Macdonald–Cartier Freeway
290px Highway 401 within Southern Ontario
Route information
Maintained by the Ministry of Transportation of Ontario
Length:	828.0 km (514.5 mi)
History:	Proposed 1938 Opened December 1947 – October 11, 1968 Extended June 28 and November 21, 2015
Major junctions
West end:	Ojibway Parkway in Windsor
	E. C. Row Expressway in Windsor  Highway 402 in London  Highway 403 near Woodstock Highway 407ETR near Milton   Highway 403 / Highway 410 in Mississauga  Highway 427 in Toronto  Highway 409 in Toronto  Highway 400 in Toronto  Highway 404 / Don Valley Parkway in Toronto Road 412 in Whitby Road 418 in Clarington Highway 137 to I-81  Highway 416 towards Ottawa
East end:	A-20 towards Montreal, QC
Location
Major cities:	Windsor, London, Kitchener, Cambridge, Mississauga, Toronto, Oshawa, Kingston and Cornwall
Highway system
Ontario provincial highways List 400-series Former ← Highway 400 Highway 402 →

King's Highway 401, commonly referred to as Highway 401 and also known by its official name as the Macdonald–Cartier Freeway or colloquially referred to as the four-oh-one, is a controlled-access 400-series highway in the Canadian province of Ontario. It stretches 828 kilometres (514 mi) from Windsor in the west to the Ontario–Quebec border in the east. The part of Highway 401 that passes through Toronto is North America's busiest highway, and one of the widest. Together with Quebec Autoroute 20, it forms the road transportation backbone of the Quebec City–Windsor Corridor, along which over half of Canada's population resides. It is also a Core Route in the National Highway System of Canada. The route is maintained by the Ministry of Transportation of Ontario (MTO) and patrolled by the Ontario Provincial Police. The speed limit is 100 km/h (62 mph) throughout its length, with the only exceptions the posted 80 km/h (50 mph) limit westbound in Windsor and in most construction zones.

By the end of 1952, three individual highways were numbered "Highway 401": the partially completed Toronto Bypass between Weston Road and Highway 11 (Yonge Street); Highway 2A between West Hill and Newcastle; and the Scenic Highway between Gananoque and Brockville, now known as the Thousand Islands Parkway. These three sections of highway were 11.8, 54.7 and 41.2 km, (7.3, 34.0 and 25.6 mi), respectively. In 1964, the route became fully navigable from Windsor to the Ontario–Quebec border. In 1965 it was given a second designation, the Macdonald–Cartier Freeway, in honour of two Fathers of Confederation. At the end of 1968, the Gananoque–Brockville section was bypassed and the final intersection grade-separated near Kingston, making Highway 401 a freeway for its entire 817.9-km length. On August 24, 2007, the portion of the highway between Glen Miller Road in Trenton and the Don Valley Parkway / Highway 404 Junction in Toronto was designated the Highway of Heroes, as the road is travelled by funeral convoys for fallen Canadian Forces personnel from CFB Trenton to the coroner's office in Toronto. On September 27, 2013, the Highway of Heroes designation was extended west to Keele Street in Toronto, to coincide with the move of the coroner's office to the new Forensic Services and Coroner's Complex at the Humber River Hospital.

In 2011, construction began on a westward extension called the "Rt. Hon. Herb Gray Parkway". This new route follows but does not replace, the former Highway 3 between the former end of the freeway and the E. C. Row Expressway, at which point it turns and parallels that route towards the site of the future Gordie Howe International Bridge. An 8-kilometre (5 mi) section of the parkway, east of the E. C. Row interchange, opened on June 28, 2015, with the remaining section completed and opened on November 21. In Summer 2019, widening of the highway between Highway/Regional Road 8 in Kitchener to Highway/Regional Road 24 in Cambridge to 12 lanes was completed. There are plans underway to widen the remaining four-lane sections between Windsor and London to six lanes and to widen the route between Cambridge and Milton as well as through Oshawa. The expansive twelve-plus-lane collector–express system now existing from Pickering through Toronto partway across Mississauga, and is currently being extended west through Mississauga to Milton.

Route description

File:Highway 401 cropped.png

The widest segment of Highway 401 is near Toronto Pearson International Airport, with 18 through lanes. Also shown is the Dixie Road interchange.

Highway 401 extends across Southwestern, Central and Eastern Ontario. In anticipation of the future expansion of the highway, the transportation ministry purchased a 91.4-metre-wide (300 ft) right-of-way along the entire length. Generally, the highway occupies only a portion of this allotment. It is one of the world's busiest highways; a 2016 analysis stated the annual average daily traffic (AADT) count between Weston Road and Highway 400 in Toronto was nearly 420,000, while a second study estimates that over 500,000 vehicles travel that section on some days. This makes it North America's busiest roadway, surpassing the Santa Monica Freeway in Los Angeles and I-75 in Atlanta. The just-in-time auto parts delivery systems of the highly integrated automotive industry of Michigan and Ontario have contributed to the highway's status as the world's busiest truck route, carrying 60 percent of vehicular trade between Canada and the US.

Highway 401 also features North America's busiest multi-structure bridge at Hogg's Hollow in Toronto. The four bridges, two for each direction with the collector and express lanes, carried an average of 373,700 vehicles daily in 2006. The highway is one of the major backbones of a network in the Great Lakes region, connecting the populous Quebec City–Windsor corridor with Michigan, New York and central Ontario's cottage country. It is the principal connection between Toronto and Montreal, becoming Autoroute 20 at the Ontario–Quebec border.

Southwestern Ontario

Highway 401 does not yet extend the last few kilometres to Detroit; an extension to Brighton Beach (at the Canada–US border in Windsor) was completed in November 2015, after which the Gordie Howe International Bridge will extend Highway 401 across the Canada–United States border to a connection through Delray to Interstate 75 in Michigan by the end of 2024. At present, Highway 401 begins as a six-lane freeway at the west end of the E. C. Row Expressway. At the Dougall Parkway, the highway turns east and exits Windsor. From here, Highway 401 mostly parallels the former route of Highway 98 from Windsor to Tilbury.

Highway 401 widens to six lanes at Highway 402 in London.

Southwestern Ontario is flat, primarily agricultural land, that takes advantage of the fertile clay soil deposited throughout the region. The main river through the region is the Thames River, which drains the second largest watershed in southern Ontario and largely influences the land use surrounding the highway. It parallels the route to the north between Tilbury and Woodstock.

Near Tilbury, Highway 401 loses its tall wall median barrier and narrows to four lanes, following lot lines laid between concession roads in a plan designed to limit damage to the sensitive agricultural lands through which the highway runs. Here the highway's flat and straight route is notorious for leading to driver inattention. The section from Windsor to London (especially west of Tilbury) has become known for deadly car accidents and pile-ups, earning it the nickname Carnage Alley. As the highway approaches London, Highway 402 merges in, resulting in a six-lane cross-section. Within London, it intersects the city's two municipal expressways, Highbury Avenue and the Veterans Memorial Parkway.

The section between London and Woodstock generally parallels the former Highway 2 but lies on the south side of the Thames River. This area is not as flat but the highway is generally straight. This part of Highway 401 often experiences heavy snowsqualls in early winter, sometimes extending as far east as Toronto. To the south of Woodstock, Highway 401 curves northeast and the western terminus of Highway 403 merges into it. From here the highway heads towards Kitchener and Cambridge, substantially north of the route of the former Highway 2 as Highway 403 assumes the role of paralleling the former Highway 2 all the way to Mississauga. Heading towards Kitchener the highway intersects with Highway 8 and returns to its eastward orientation. From Highway/Regional Road 8 to Highway/Regional Road 24 in Cambridge the highway has recently been widened to 12 lanes in order to accommodate the large amount of traffic which uses Highway 8, then Highway 401 and then Regional Road 24 to travel between Kitchener and Cambridge. Beyond Highway/Regional Road 24, the highway returns to a six-lane cross section and meanders towards Milton, passing through hills and rock cuts along the way.

File:Highway 401's busiest point.jpg

Highway 401 at Weston Road has a volume of over 500,000 vehicles per day during the summer months.

Greater Toronto Area

See also: Local-express lanes

As Highway 401 approaches the Greater Toronto Area (GTA), it descends through the ecologically protected Niagara Escarpment to the west of Milton. Upon entering the town, it enters the first urbanized section of the GTA, passing through two rural areas between there and Oshawa. The first rural gap is the western side of Toronto's Greenbelt, a zone around Toronto protected from development. After this 10 km (6.2 mi) gap, the highway interchanges with the Highway 407 Express Toll Route. Within the GTA, the highway passes several major shopping malls including Yorkdale Shopping Centre, Scarborough Town Centre and Pickering Town Centre.

File:King's Highway 401 - Ontario (4118738546).jpg

Different colours are used on the signs on Highway 401's collector-express system to avoid confusion. The express lanes use green signs and the collector lanes use blue.

Highway 401 widens into a collector-express system as it approaches Mavis Road in Mississauga, a concept inspired by the Dan Ryan Expressway in Chicago. The system divides each direction of travel into collector and express lanes, giving the highway a wide span and four carriageways. To avoid confusion between carriageways, blue signs are used for the collector lanes and green signs for the express lanes. Unlike the collector lanes, which provide access to every interchange, the express lanes only provide direct access to a select few interchanges. Access between the two is provided by transfers, which are strategically placed to prevent disruptions caused by closely spaced interchanges. The overall purpose of the collector-express system is to maximize traffic flow for both local and long-distance traffic. In addition, Highway 401 was equipped with a traffic camera system called COMPASS in early 1991. Using closed-circuit television cameras, vehicle detection loops and LED changeable-message signs, COMPASS enables the MTO Traffic Operations Centre to obtain a real-time assessment of traffic conditions and alert drivers of collisions, congestion and construction. The system stretches from the Highway 403 / 410 interchange in Mississauga to Harwood Avenue in Ajax.

"The Basketweave", just east of the Highway 400 interchange, is a free-flowing crossover between the collector and express lanes.

Two sets of collector-express systems exist in the GTA. The first set is 6.6 km (4.1 mi) long and connects Highway 403, Highway 410 and Highway 427, initially terminating just west of Highway 410 in the early 1990s, but since the 2010s has extended westward in stages to include the interchanges with Hurontario Street and Mavis Road, with a final extension to just east of Winston Churchill Boulevard presently under construction as of 2020. This system was original designed to accommodate and organize various traffic movements from the Highway 403 / 410 and Highway 427 interchanges along Highway 401, replacing an earlier plan that would have run Highway 403 directly to Eglinton Avenue and the never-built Richview Expressway. East of the interchange with Renforth Drive, the collector lanes diverge to become the on-ramps to Highway 427 northbound and southbound. The second 43.7 km (27.2 mi) system starts from Highway 409 and passes through the centre of Toronto, ending at Brock Road in Pickering to the east. The 5 km (3.1 mi) gap between the two systems is a traffic bottleneck. However, the interchange with Highway 427 cannot accommodate future widening of Highway 401.

File:Highway 401 Densification.jpg

Highway 401 looking west from Don Mills Road overpass, with the Concord Park Place condo development and North York General Hospital in the background.

Highway 401 widens to 18 lanes south of Toronto Pearson International Airport. Progressing eastward, eight lanes are carried beneath the large spaghetti junction at Highway 427. The highway curves northeast and follows a power transmission corridor to Highway 409, which merges with the mainline and forms the collector lanes. It returns to its eastward route through Toronto, now carrying 12–16 lanes of traffic on four carriageways. Highway 401 is often congested in this section, with an average of 442,900 vehicles passing between Weston Road and Highway 400 per day as of 2008. In spite of this congestion, it is the primary commuting route in Toronto; over 50 percent of vehicles bound for downtown Toronto use the highway. East of Highway 400 is The Basketweave, as each direction has a criss-crossing transfer between the express and collectors carriageways. Near Yorkdale Shopping Centre, twelve lanes pass beneath a complicated interchange with Allen Road, built to serve the cancelled Spadina Expressway. Further east, the highway crosses Hogg's Hollow, over the West Don River and Yonge Street in the centre of Toronto, the busiest multi-span bridge crossing in North America, surpassing the Brooklyn Bridge. It then crosses the East Don River and climbs toward an interchange with the Don Valley Parkway and Highway 404, which provides access to downtown Toronto and the suburbs to the north, respectively.

File:Concord Park Place construction site 2009.JPG

Highway 401 just west of Leslie Street

Progressing eastward in Scarborough, the Highway 401 continues through mostly residential areas and Scarborough City Centre including the shopping mall, eventually reaching the city's eastern edge where former Highway 2A merges into it at a vast interchange with Kingston Road and Port Union Road, and crossing the Rouge Valley into Pickering.

West of Pickering, Highway 401 again meets former Highway 2, which thereafter parallels it to the Ontario–Quebec border. As the highway approaches Brock Road in Pickering, the collector and express lanes converge, narrowing the 14-lane cross-section to 10, divided only at the centre. It remains this width as it passes into Ajax, before narrowing to six lanes at Salem Road. Planned expansions east of Salem to improve flow leading into the Highway 412 and Lakeridge Road interchanges will see the highway widened to ten lanes as far as Brock Street in Whitby, where the existing interchange will be reconfigured.

East of Ajax, the highway passes through the second 3.5 km (2.1 mi) rural gap, and enters Whitby. The stretch of Highway 401 through Whitby and Oshawa features several structures completed during the initial construction of the highway in the 1940s. Several of these structures are to be demolished, either due to their age, or to prepare for the planned widening of Highway 401 through this area. A former Canadian National Railway overpass, which was fenced off but commonly used by pedestrians during Highway of Heroes repatriations, was demolished on the night of June 11, 2011. A second structure in Bowmanville was demolished during two overnight closures on July 9 and 16. At Harmony Road, the suburban surroundings quickly transition to agricultural land. The highway curves around the south side of Bowmanville and travels towards Highway 35 and Highway 115.

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  Highway 401 looking east between Avenue Road and Yonge Street; the North York skyline is visible in the distance

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  Highway 401 at the interchange with Highway 410 and Highway 403 in Mississauga

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  Traffic cameras are mounted at every exit within Toronto and form one part of the COMPASS system.

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  The collector-express system just east of the Highway 400 interchange, with the "Basketweave" transfers between them in the background.

• Snowy Higddhway 4012.jpg

  Winter conditions on Highway 401 in Toronto due to a snowsquall.

Eastern Ontario

Through much of eastern Ontario, Highway 401 is a rural freeway with a grass median.

From east of Highway 35 and Highway 115 to Cobourg, Highway 401 passes through a mix of agricultural land and forests, maintaining a straight course. Just east of Cobourg, the highway narrows to four lanes and the terrain becomes undulating, with the highway routed around hills and through valleys along the shores of Lake Ontario. At Trenton, the highway crosses the Trent Canal and returns to an agricultural setting. It then crosses the Moira River as it goes through Belleville before heading eastward to Kingston. The Kingston portion of the highway, originally named the Kingston-Bypass, was one of the first sections of the highway to be completed; it is now mostly three lanes each way.

Highway 401 ends at the Quebec border, where Autoroute 20 continues towards Montreal and the Maritime provinces.

East of Kingston, the highway continues through a predominantly agricultural area alongside the Saint Lawrence River to Gananoque, where it splits with the Thousand Islands Parkway, one of the original sections of the highway designated in 1952. The current Highway 401 runs parallel to the parkway several kilometres inland from the river. The Canadian Shield, an ancient geological formation, appears through this heavily forested section of the highway. Highway 401 rejoins the Thousand Islands Parkway immediately southwest of Brockville, now heading northeast.

The remainder of the highway runs parallel to the former Highway 2 along the shore of the Saint Lawrence River within the Saint Lawrence Valley. Northeast of Brockville is the interchange with Highway 416, which heads north to Ottawa. At the Ontario–Quebec border, Highway 401 becomes Autoroute 20 and continues to Montreal.

Traffic volume

The MTO publishes yearly traffic volume data for provincial highways, expressed as an average daily vehicle count over the span of a year (AADT). The table below compares the AADT at several locations along Highway 401 using data from 1969, 1988, 2008 and 2016.

Average annual daily traffic counts of selected sections of Highway 401 over 47 years

Location	Section	Traffic volume (AADT)
		1969	1988	2008	2016
Windsor	Dougall Parkway – Essex County Road 46	9,550	13,200	16,700	17,500
London	Highbury Avenue – Veterans Memorial Parkway	17,450	33,800	64,500	64,200
Woodstock	Oxford County Road 59 – Highway 403	16,700	35,100	67,100	67,500
Cambridge	Highway 8 – Highway 24	19,900	50,400	125,600	137,300
Mississauga	Mississauga Road – Hurontario Street	28,450	97,100	177,300	216,500
Toronto	Weston Road – Highway 400	106,850	319,600	442,900	416,500
Oshawa	Stevenson Road – Simcoe Street	29,000	79,000	120,700	134,200
Belleville	Highway 62 – Highway 37	13,750	22,500	43,500	45,300
Kingston	Frontenac County Road 38 – Sydenham Road	12,000	20,700	45,400	55,000
Brockville	Highway 29 – North Augusta Road	10,050	15,300	29,100	33,600
Cornwall	Highway 138 – McConnell Avenue	10,300	12,900	18,400	21,400

Number of through lanes on Highway 401 (excludes ongoing or planned widening projects)

Location	Lane count	Distance
E C Row Expressway to Essex County Road 42	6 lanes	55.7 km (34.6 mi)
Essex County Road 42 to Highway 402	4 lanes	127.5 km (79.2 mi)
Highway 402 to Highway 8	6 lanes	94.6 km (58.8 mi)
Highway 8 to Highway 24	12 lanes	3.0 km (1.9 mi)
Highway 24 to Credit River	6 lanes	56.3 km (35.0 mi)
Credit River to Highway 403 / 410	12-lane collector-express system	5.6 km (3.5 mi)
Highway 403/ 410 to Highway 427	18-lane collector-express system	5.8 km (3.6 mi)
Highway 427 to Highway 27	8 lanes	0.8 km (0.50 mi)
Highway 27 to Highway 409	10 lanes	3.9 km (2.4 mi)
Highway 409 to Brock Road	12–16-lane collector-express system	43.3 km (26.9 mi)
Brock Road to Salem Road	10 lanes	6.0 km (3.7 mi)
Salem Road to 4.5 km east of Baltimore Street	6 lanes	74.8 km (46.5 mi)
4.5 km east of Baltimore Street to Frontenac County Road 38	4 lanes	131.7 km (81.8 mi)
Frontenac County Road 38 to Highway 15	6 lanes	12.2 km (7.6 mi)
Highway 15 to ON–QC border	4 lanes	205.0 km (127.4 mi)

History

Predecessors

Main articles: Lakeshore Road, The Middle Road, Highway 2, and Highway 2A

Highway 401 colour-coded by the year each section opened to traffic

Highway 401's history predates its designation by over two decades. As automobile use in southern Ontario grew in the early 20th century, road design and construction advanced significantly. Following frequent erosion of Lake Shore Road, then macadamized, a concrete road known as the Toronto–Hamilton Highway was proposed in January 1914. Construction began on November 8 of that year, following the onset of World War I. The highway was designed to run along the lake shore, instead of Dundas Street to the north, because the numerous hills encountered along Dundas would have increased costs without improving accessibility. Middle Road, a dirt lane named because of its position between the two, was not considered since Lake Shore and Dundas were both overcrowded and in need of serious repairs. The road was formally opened on November 24, 1917, 5.5 m (18 ft) wide and nearly 64 km (40 mi) long. It was the first concrete road in Ontario, as well as one of the longest stretches of concrete road between two cities in the world.

Over the next decade, vehicle usage increased substantially, and by 1920, Lakeshore Road was again congested, particularly during weekends. In response, the Department of Highways examined improving another road between Toronto and Hamilton. The road was to be more than twice the width of Lakeshore Road at 12 m (39 ft) and would carry two lanes of traffic in either direction. Construction on what was then known as the Queen Street Extension west of Toronto began in early 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 autobahns—new "dual-lane divided highways"—modified the design for Ontario roads, and McQuesten ordered the Middle Road be converted into this new form of highway. A 40 m (130 ft) right-of-way was purchased along the Middle Road and construction began to convert the existing sections to a divided highway. Work also began on Canada's first interchange at Highway 10.

File:Thousand Islands Parkway, 1944.png

Finished grading of the Thousand Islands Parkway (Highway 2S) in 1944

Beginning in 1935, McQuesten applied the concept of a dual-highway to several projects along Highway 2, including along Kingston Road in Scarborough Township. When widening in Scarborough reached the Highland Creek ravine in 1936, the Department of Highways began construction on a new bridge over the large valley, bypassing the former alignment around West Hill. From here the highway was constructed on a new alignment to Oshawa, avoiding construction on the congested Highway 2. As grading and bridge construction neared completion on the new highway between West Hill and Oshawa in September 1939, World War II broke out and gradually tax revenues were re-allocated from highway construction to the war effort. At the same time, between September 6 and 8, 1939, the Ontario Good Roads Association Conference was held at Bigwin Inn, near Huntsville, drawing highway engineers from across North America to discuss the new concept of "Dual Highways." On the first day of the convention, McQuesten announced his vision of the freeway: an uninterrupted drive through the scenic regions of Ontario, discouraging local business and local traffic from accessing the highway except at infrequent controlled-access points. It was announced in the days thereafter this concept would be applied to a new "trans-provincial expressway", running from Windsor to the Ontario–Quebec border.

The former Highway 2A near Highland Creek, aside from a resurfaced pavement, has not been altered since it opened in 1947.

Highway engineers evaluated factors such as grading, curve radius, and the narrow median used along the Middle Road—which was inaugurated on August 23, 1940 as the Queen Elizabeth Way (QEW)—and began to plan the course of a new dual highway mostly parallel to Highway 2, with precedence given to areas most hampered by congestion. Unlike the QEW, this highway would not be built along an existing road, but rather on a new right-of-way, avoiding the need to provide access to properties. Along with immense improvements to machinery and construction techniques over its six-year course, the war provided planners an opportunity to conduct a survey of 375,000 drivers, asking them about their preferred route to travel to their destination. Using this information, a course was plotted from Windsor to Quebec, bypassing all towns along the way.

Highway 2S (S for Scenic) was the first completed section of new roadway. Built to connect with the Thousand Islands Bridge at Ivy Lea and opened as a gravel road in late 1941 or early 1942, the road followed the shore of the Saint Lawrence River and connected with the western end of the twinned Highway 2 near Brockville. In addition, the highway between Highland Creek and Oshawa was opened as a gravel-surfaced road in May 1942.

Following the war, construction resumed on roadways throughout Ontario. The expressway between Highland Creek and Oshawa was completed in December 1947, while other sections languished. The Toronto–Barrie Highway was the primary focus of the Department of Highways at the time, and the onset of the Korean War in 1950 stalled construction again. Despite the delays, highway minister George Doucett officially announced the plans for construction of the new trans-provincial expressway that year, with the Toronto to Oshawa expressway serving as a model for the design. Work on the most important link, the Toronto Bypass, began in 1951, but it would not open with that name.

The Highway 400 interchange in 1953. Today, the former cloverleaf has been replaced with a multilevel interchange.

Assumption

In July 1952 (possibly July 1, the same day Highway 400 was numbered), the Highland Creek to Oshawa expressway and Highway 2S were designated Controlled-Access Highway No 401, a move scorned by one critic because of the lack of thought given to the numbered name. Construction was completed for several sections of the Toronto Bypass: between Highway 400 and Dufferin Street in August, west to Weston Road in September, east to Bathurst Street in October and finally to Yonge Street in December. Extensions east and west began in 1953; the eastern extension to Bayview Avenue opened in April 1955, but the western extension was delayed by the damage caused by Hurricane Hazel on October 15, 1954, which nearly destroyed the new bridge over the Humber River. The reconstruction would take until July 8, 1955, and the highway was opened between Weston and Highway 27 in September 1955.

Within years after opening, the four-lane Toronto Bypass was congested, prompting the Department of Highways to widen this section to 12 lanes beginning in 1963.

The entire bypass, including the widening of Highway 27 into an expressway south of Highway 401, was completed in August 1956. Upon its opening, the bypass was described by one reporter as "a motorist's dream" providing "some of the most soothing scenery in the Metropolitan area". The reporter continued, with regard to the eastern section through Scarborough, that it "winds smoothly through pastures across streams and rivers, and beside green thickets. It seems a long way from the big city." By 1959 however, the bypass was a lineup of cars, as 85,000 drivers crowded the roadway, designed to handle a maximum of 48,000 vehicles, on a daily basis. Motorists found the new road to be a convenient way of travelling across Toronto; this convenience helped influence the suburban shift in the city and continues to be a driving force of urban sprawl today.

Meanwhile, beyond Toronto, the highway was being built in a patchwork fashion, focusing on congested areas first. Construction west from Highway 27 began in late 1954, as did the Kingston Bypass in Eastern Ontario. Work began to connect the latter with the Scenic Highway in 1955. After the 1954 New York State Thruway opened from Buffalo to New York City, Michigan officials encouraged Ontario to bypass Highway 3 as the most direct path from Detroit to Buffalo. By 1956, construction had begun on a segment between Highway 4 in London and Highway 2 in Woodstock, as well as on the section between Windsor and Tilbury.

A plaque near Brockville commemorates the official completion of the highway.

In 1958, a section bypassing Morrisburg was opened to accommodate traffic displaced from a portion of Highway 2 through The Lost Villages of the Saint Lawrence Seaway.

By the end of 1960, the Toronto section of the highway was extended both eastwards and westwards: first, to the east between Newcastle and Port Hope on June 30, then later to the west between Highway 25 in Milton and Highway 8 south of Kitchener on November 17. By mid-1961, the section between Brighton and Marysville had opened. The gap to the east, from Highway 28 in Port Hope to Highway 30 in Brighton was opened on July 20, 1961.

The gap between Woodstock and Kitchener was completed on November 9, 1961, while the gap between Tilbury and London was completed two lanes at a time; the westbound lanes on October 22, 1963, the eastbound on July 20, 1965. The gap between Marysville and Kingston was opened by 1962. The final sections, from west of Cornwall to Lancaster, were opened between 1962 and 1964; two lanes opened to Lancaster on September 11, 1962, but the other two were not completed until July 31, 1964. The last segment, to the Ontario–Quebec border, was opened on November 10, 1964. Finally, on October 11, 1968, the Thousand Islands Bypass opened. This final piece was commemorated with a plaque to signify the completion of Highway 401.

Expansion

The widening of Highway 401 from four to twelve lanes in Toronto took nine years and was accomplished with at least four lanes open at all times. Shown here is the Highway 401 / Don Valley Parkway / Highway 404 interchange under construction in 1965.

In Toronto, engineers and surveyors were examining the four-lane bypass, while planners set about designing a way to handle the commuter highway. In 1963, transportation minister Charles MacNaughton announced the widening of Highway 401 in Toronto from four to a minimum of 12 lanes between Islington Avenue and Markham Road. The design was taken from the Dan Ryan Expressway in Chicago, which was widened into a similar configuration around the same time. Construction began immediately. While the plan initially called for construction to end in 1967, it continued for nearly a decade. At least four lanes were always open during the large reconstruction project, which included complex new interchanges at Highway 27, Highway 400, the planned Spadina Expressway and the Don Valley Parkway. The system was completed in 1972, along with the Highway 27 (renamed Highway 427) bypass between the QEW and Pearson Airport. Most of the interchanges in Toronto were reconstructed as partial cloverleafs and a continuous lighting system was installed.

On January 11, 1965, at the dinner celebration of Sir John A. Macdonald's 150th birthday, the Premier of Ontario John Robarts designated Highway 401 the Macdonald–Cartier Freeway to honour Macdonald and George-Étienne Cartier, two of Canada's Fathers of Confederation. Unlike other names later applied to the highway, the Macdonald–Cartier Freeway designation covers the entire length of Highway 401. Signs designating the freeway and shields with the letters 'M-C' were installed, but these had been removed by 1997. In 2003, 38 years after Robarts' naming of the highway, a Member of Provincial Parliament attempted to get the Macdonald-Cartier Freeway highway name enshrined into law; the bill only passed first reading and was not enacted.

In the 1970s, Highway 401 was widened to six lanes in Durham. Between 1977 and 1982, Highway 401 was widened from four to six lanes between Hurontario Street (Highway 10) to Highway 25, with the Jersey median barrier making its debut in Ontario in that segment.

The Highway 401-403-410 interchange looking east in 1987. At the time the Highway 401 collector and express lanes merged prior to crossing Tomken Road. At the time Highway 410 was only a Super two highway which connected to Highway 401 east of the interchange.

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The expanded interchange looking north in 2013, showing the flyover ramps between Highway 401 and Highway 410 with the Highway 401 express lanes underneath them.

The 1980s saw more sections widened. Most significant was the new collector-express system between Highway 403 / 410 and Highway 427, including a new set of flyover ramps from the express lanes to Highway 403 which opened in 1984, while a basketweave transfer between the eastbound collector and express lanes near Pearson Airport was completed in mid-1985. After the Kennedy Road overpass was replaced, cast-in-place concrete flyover ramps were constructed from 1988 to late 1990 to link up Highway 401 and Highway 410, notably the 11-span flyover ramp from Highway 401 eastbound to Highway 410 northbound which remains the longest in the Greater Toronto Area, while the Highway 410 southbound to Highway 401 eastbound flyover replaced a loop ramp. In the fall of 1991, alongside the widening of Highway 410 into a full freeway, construction began on the connecting ramps between Highway 403 and Highway 410, which pass under the existing bridge structures carrying Highway 401 (which would soon be designated as the collector lanes), while new overpasses were constructed for the Highway 401 express lanes which were extended from east of Tomken Road to just east of Kennedy Road.

Highway 401 at Meadowvale Road in 1989, before being widened to a 14-lane collector-express system

Plans were made to extend the eastern system from Neilson Road to Brock Road in Pickering in the late 1980s, but took over a decade to reach fruition by 1997. This was followed shortly thereafter by the widening of the highway through Ajax and a new interchange at Pickering Beach Road (renamed Salem Road) and Stevenson Road.

The 1990s also saw the first step in widening the highway from Toronto to London, by replacing the grass median with the addition of a third traffic lane per direction separated by a tall-wall concrete median barrier. The segment from London to Woodstock received this upgrade first, with the expansion ending near the terminus of Highway 403's newly constructed western segment. A project in the mid-1990s brought the highway up to a minimum of six lanes between Highway 8 in Kitchener and Highway 35 / 115 in Newcastle. Other projects prepared sections for eventual widening.

In 1993, the stretch of Highway 401 eastbound near Milton and westbound near Whitby had chevrons painted in each lane in an effort to reduce tailgating, a concept borrowed from France and Britain. Signs advised motorists to keep at least two chevrons apart, in essence warning them not to follow too closely. Some of these chevrons remained intact in the westbound lanes in Whitby until 2012, though the signs stating their use had been removed.

Advantage I-75

Between June 1990 and 1998, Highway 401 and Interstate 75 were used for a pilot project named Advantage I-75 to test the reliability and versatility of an automated tracking system for transport trucks. Termed "MACS" (Mainline Automated Clearance System), it allows a truck to travel from Florida to Ontario without a second inspection. MACS was initially tested at two truck inspection stations in Kentucky, with transponders installed in 220 trucks. Exact time, date, location, weight and axle data were logged as a truck approached an equipped station. Following initial tests, MACS was deployed at every inspection station along I-75 from Miami to Detroit, and along Highway 401 from Windsor to Belleville in 1994. The project demonstrated the effectiveness of electronic systems in enforcing freight restrictions without delaying vehicles, while alleviating security fears such systems could be compromised. The concept has since been applied to many parts of Canada, including Highway 407's electronic tolling system.

"Carnage Alley"

The 87-vehicle pile up on September 3, 1999

The section of Highway 401 between Windsor and London has often been referred to as Carnage Alley, in reference to the numerous crashes that have occurred throughout its history. The term became more commonplace following several deadly pileups during the 1990s. The narrow and open grass median was an ineffective obstacle in preventing cross-median collisions. The soft shoulders consisted of gravel, with sharp slopes which were blamed for facilitating vehicle rollovers. The nature of that section of highway, described as a mainly straight road with a featureless agricultural landscape, was said to make drivers feel less involved and lose focus on the road. In winter, the area between Woodstock and Chatham is also subject to sudden snow squalls from lake-effect snow. Several collisions have resulted from motorists deviating from their lane and losing control of their vehicles.

Various other names, including The Killer Highway circulated for a time, but Carnage Alley became predominant following an 87-vehicle pile-up on September 3, 1999 (the start of Labour Day weekend), the worst in Canadian history, that resulted in eight deaths and 45 injured individuals.

File:Highway 401 at Highway 98 facing southwest towards Windsor.png

Highway 401 facing southwest in 1958, at the interchange with then-Highway 98 (now Provincial Road) in the foreground, and the split at Dougall Parkway in the background. This segment would be reconstructed in 2008-10.

Only a few days prior, then-Transportation Minister David Turnbull had deemed the highway "pleasant" to drive. On the morning of September 3, the local weather station reported clear conditions due to a malfunction, while a thick layer of fog rolled onto the highway. Dozens of vehicles, including several semi-trailers, quickly crashed into each other shortly after 8 a.m., one following another in the dense fog, and the accumulating wreckage caught traffic travelling in the opposite direction. Immediately following the crash, the MTO installed paved shoulders with rumble strips and funded additional police to patrol the highway, a move criticized as being insufficient.

Beginning in 2004, 46 km (29 mi) of the highway was widened from four asphalt lanes to six concrete lanes, paved shoulders were added, and a concrete Ontario Tall Wall median was installed, which was the solution the Canadian Automobile Association promoted in 1999. Interchanges were improved and signage was upgraded as part of a five-phase project to improve Highway 401 from Highway 3 in Windsor to Essex County Road 42 (formerly Highway 2) on the western edge of Tilbury. From 2008 to 2010, with joint funding from the provincial and federal governments, the section of Highway 401 from Dougall Parkway (former Highway 3B) to Provincial Road (former Highway 98) was widened to six lanes, necessitating the replacement of the Walker Road and Provincial Road underpasses for the freeway's elevated section. As part of that project, the Dougall Parkway split with Highway 401 was reconfigured, replacing a one-lane 1950s-era underpass tunnel with a modern high-speed flyover ramp. The old interchange had reduced eastbound Highway 401 traffic to one lane as it merged with Dougall Parkway, whereas the new interchange allows three lanes per direction of Highway 401 to pass through.

Highway of Heroes

"Highway of Heroes" redirects here. For other uses, see List of highways named Highway of Heroes.

Canadians line overpasses along the Highway of Heroes to pay their respects to fallen soldiers.

On August 24, 2007, the MTO announced the stretch of Highway 401 between Glen Miller Road in Trenton and the intersection of the Don Valley Parkway and Highway 404 in Toronto would bear the additional name Highway of Heroes (French: Autoroute des héros), in honour of Canadian soldiers who have died, though Highway 401 in its entirety remains designated as the Macdonald–Cartier Freeway. This length of the highway is often travelled by a convoy of vehicles carrying a fallen soldier's body, with his or her family, from CFB Trenton to the coroner's office at the Centre for Forensic Sciences in Toronto. Since 2002, when the first fallen Canadian soldiers were repatriated from Afghanistan, crowds have lined the overpasses to pay their respects as convoys pass.

The route marker for the Highway of Heroes

The origin of the name can be traced to an article in the Toronto Sun on June 23, 2007, by columnist Joe Warmington, in which he interviewed Northumberland photographer Pete Fisher. Cobourg resident Ron Flindall was responsible for organizing the first bridge salutes following the loss of four soldiers on April 18, 2002.

Warmington described the gathering of crowds on overpasses to welcome fallen soldiers as a "highway of heroes phenomena". This led a Cramahe Township volunteer firefighter to contact Fisher on July 10 about starting a petition, leading Fisher to publish an article which was posted to the Northumberland Today website. The online article eventually caught the attention of London resident Jay Forbes. Forbes began a petition, which received over 20,000 signatures before being brought to the Minister of Transportation on August 22. Following the announcement on August 24, the provincial government and MTO set out to design new signs. The signs were erected and unveiled on September 7, and include a smaller reassurance marker (shield), as well as a larger billboard version.

Highway improvements and safety concerns

London and Kitchener

Highway 401 was widened in 2008 between Highway 402 and Wellington Road in London. Additional widening west of Highway 402 is planned.

Between 2006 and 2008, Highway 401 was widened from four to six lanes between Highway 402 and Wellington Road in London. This included reconfiguring the Wellington Road interchange from a cloverleaf to a Parclo A4 while replacing the original 1956 overpass with a longer and wider structure.

In November 2010, the widening of Highway 401 from four to six lanes between Woodstock and Kitchener was completed after many years of planning and construction. The project included the installation of a tall-wall median barrier, straightening curves and adding additional interchanges on the freeway, allowing it to be easily vacated in an emergency event.

Greater Toronto Area

In the late 1990s, several prerequisite projects were undertaken for the future widening of Highway 401 throughout Mississauga, including a new underpass structure to accommodate Derry Road which was widened from two to six lanes (1996–97), the addition of an interchange with the Mavis Road extension in 1999 whose overpass was designed to be lengthened with two outer spans, and replacing the Mississauga Road overpass which began on February 15, 2002 (in a cost-sharing agreement between the province and Peel Region), although that section of the freeway would retain its six-lane cross section for the next decade. More recent work included the replacement of the McLaughlin Road overpass in 2008. Starting in 2009, Highway 401's collector-express lanes in Mississauga have been extended westward beyond its initial terminus at Highway 410. The widening of this 7 km segment to the Credit River necessitated the replacement of several existing overpasses, including those of Hurontario Street (2013) and Second Line West (2016), with the Second Line West crossing rebuilt as a pedestrian/cyclist bridge since most vehicular traffic was already rerouted to the Mavis Road extension. Tying into this extension of Highway 401's collector-express system, the missing ramps from Highway 401 eastbound to Highway 403 westbound and the opposite movement were completed in 2018 which also provided direct access to Cawthra Road, making the Highway 401-403-410 junction a full four-way interchange. The first phase of this expansion to west of Hurontario Street, a distance of 2.8 km (1.7 mi), opened in 2013, while the second phase to the Credit River was completed in 2020.

Beginning in 1998, several projects were initiated on Highway 401 within Toronto. The freeway's pavement through the city was resurfaced. The most significant construction work was widening the route from six to eight lanes though the Highway 427 interchange in 2005, which necessitating the replacement of the Highway 27 underpass, although the rest of the junction's flyovers could accommodate the expansion. Some projects have been completed during overnight construction projects, including the widening and rehabilitation of the Hogg's Hollow bridge, the replacement of the original gantries throughout the collector-express system, and rehabilitating the flyover ramps of the Highway 401 / 400 interchange.

An empty Highway 401 through Toronto following a series of propane explosions in 2008.

On August 10, 2008, following a series of explosions at a propane facility in Toronto, Highway 401 was closed between Highway 400 and Highway 404 as a precautionary measure, the largest closure of the highway in its history. The highway remained closed until 8 p.m., though several exits near the blast remained closed thereafter.

In Oshawa, exit 416 (Park Road) was replaced by a new interchange at exit 415 (Stevenson Road). The contract, which began September 7, 2005, included the interchange and the resurfacing of 23.4 km (14.5 mi) of the highway between Oshawa and Highway 35 / Highway 115. The westbound ramps were opened in mid-September 2007 and the eastbound ramps in mid-2009. The resurfacing was completed mid-2010.

In 2013, as a prerequisite to construction of the West Durham Link which was eventually numbered as Highway 412, the section of Highway 401 near the Lake Ridge Road overpass was shifted northward on a new alignment away from the parallel railway line to allow sufficient right-of-way for the interchange to the new route. The interchange to Highway 412 opened on June 20, 2016.

Rt. Hon. Herb Gray Parkway

See also: Gordie Howe International Bridge

File:Highway 401 westbound Windsor.jpg

The Highway 401 extension in Windsor, opened in 2015, is a six-lane below-grade roadway with tunnels and greenspace. It will connect to the planned Gordie Howe International Bridge.

In 2004, a joint announcement by the federal government of the United States and Government of Canada confirmed a new border crossing would be constructed between Detroit and Windsor. The Detroit River International Crossing (DRIC) was formed as a bi-national committee to manage the project. The MTO took advantage of this opportunity to extend Highway 401 to the Canada–US border and began an environmental impact assessment on the entire project in late 2005. The City of Windsor also hired New York traffic consultant Sam Schwartz to design a parkway to the border. Schwartz's proposal would eventually inspire the DRIC's own design, but his route was not chosen, with the DRIC opting instead to take a northern route. On February 8, 2008, the MTO announced it had begun purchasing property south of the E.C. Row Expressway, upsetting many area residents who had purchased properties in the years prior.

On March 3, 2008, the Michigan Department of Transportation and the MTO (in partnership with Transport Canada, the Federal Highway Administration of the United States and the Detroit River International Crossing group) completed a joint assessment on the soils along the Detroit River and determined they could indeed support the weight of a new bridge; the stability of the underlying soil and clay and the impact of the nearby Windsor Salt Mine had caused concern for all parties involved in the project.

Despite protest from area residents, as well as a dismissed lawsuit from Ambassador Bridge owner Matty Moroun, it was announced on May 1, 2008, that a preferred route had been selected and the new route would be named the Windsor–Essex Parkway. The new parkway is below-grade and has six through-lanes. It follows (but does not replace) Talbot Road and Huron Church Road from a new interchange at the former end of Highway 401 to the E. C. Row Expressway, where it runs concurrently westward for 2 km (1.2 mi). From there, it turns northwest and follows a new alignment to the border. Internally, the new parkway was numbered Highway 7901. Initial construction of a noise barrier from North Talbot Road to Howard Avenue began in March 2010; full construction began on August 19, 2011.

On November 28, 2012, the Ministry of Transportation announced a Federal Order in Council was passed to change the name of the parkway to the "Rt. Hon. Herb Gray Parkway", in honour of the Right Honourable Herb Gray, a Member of Parliament from Windsor. In early 2015, it was announced the parkway would open to traffic between Highway 3 and Labelle Street (near the E. C. Row Expressway) in the spring; an 8-kilometre (5 mi) section was opened to traffic on June 28, extending Highway 401 as far west as the E. C. Row Expressway. It was the first new segment of the highway to be opened since the Thousand Islands Bypass in 1968. The stretch to Ojibway Parkway was opened on November 21, completing the parkway as far as the planned bridge approach and border plaza. Construction on projects related to the Gordie Howe International Bridge began in 2015 with an initial completion date in 2019–20. The "Bridging North America" consortium was selected to build the bridge in July 2018. Minor construction began immediately and major construction began in fall 2018. The Gordie Howe International Bridge is expected to be completed by the end of 2024.

Future

Southwestern Ontario

Highway 401 in the Greenbelt, at the interchange with Guelph Line. The stretch of Highway 401 between Highway 8 and Highway 407 ETR is slated to be widened from six to ten lanes, including two HOV lanes.

In Southwestern Ontario, several improvements are under way to provide six lanes on Highway 401 from Windsor to Toronto, in response to the 1999 Highway 401 crash in Carnage Alley. West of Essex County Road 42 on the west of Tilbury, the highway has been widened to six lanes with a concrete divider in anticipation of the Rt. Hon. Herb Gray Parkway.

Within the London area, traffic volumes are expected to increase considerably, leading to poor highway conditions. The province has put in place an extensive plan to widen and reconstruct the London corridor between 2006 and 2021. This included building a new interchange with Wonderland Road which opened in November 2015 to help improve access to Highway 401 westbound from the city's southwest end and involved replacing the Westminster Drive overpass to allow the highway to be widened. A reconstruction of the outdated cloverleaf interchange at Colonel Talbot Road and widening Highway 401 from four to six lanes between Highway 4 and Highway 402 is also proposed. The MTO is also planning on widening Highway 401 from six to eight lanes through part of the London corridor.

In the Kitchener/Cambridge area, the Y-junction between Highway 401 and Highway 8 Expressway is to be expanded to a full all-directional interchange, with flyover ramps linking eastbound Highway 401 to Highway 8 towards Kitchener and Highway 8 traffic towards Toronto to westbound Highway 401 to bypass the existing connection using King Street, giving Highway 401 direct freeway access to the Conestoga Parkway. The widening of Highway 401 from six to twelve lanes from Highway 8 (King Street) to Highway/Regional Road 24 (Hespeler Road) commenced on June 8, 2015 and concluded in summer 2019. The second phase of expansion scheduled for 2019-21 will see Highway 401 widened from six to ten lanes between Highway/Regional Road 24 and Townline Road. At the interchange with Highway 24 (Hespeler Road), the span carrying northbound traffic which opened in 1989 was torn down on May 1, 2021, with both directions of Highway 24 traffic temporarily relocated to the overpass originally built in 1960 and designated for southbound drivers since 1989, as a new overpass is being constructed to accommodate Highway 401's expanded cross-section.

Greater Toronto Area

In its 2007 plan for southern Ontario, the MTO announced long-term plans to create high-occupancy vehicle (HOV) lanes from Mississauga Road west to Milton; by 2011 these plans had been expanded in scope to as far west as Hespeler Road in Cambridge.

File:401 widening Mississauga Road.jpg

Hwy. 401 widening work in Mississauga as seen from Mississauga Road in 2020

A successful construction consortium was announced in 2019, for further widening from the Credit River to Regional Road 25 in Milton to a minimum of 10 lanes include an HOV lane. This project includes extending the existing 12-lane collector–express system from the Credit River to just east of Winston Churchill Boulevard, while another 12-lane collector–express system will run from just west of the Highway 407 interchange to just east of the James Snow Parkway. Construction began with the replacement of the Creditview overpass in the summer of 2019. The old Trafalgar Road overpass was demolished in September 2021, and evidence of the upcoming collector lanes can be seen near the 407/401 Partial access interchange.[8]

Expansion in Durham includes widening the highway to 12 lanes, extending the current collector-express system from its end at Brock Road in Pickering to Brock Street in Whitby. A Transportation Environmental Study Report was completed on widening highway 401, extending the collector-express system easterly through to the Highway 412 interchange in Whitby, then ten lanes easterly to Liberty Street in the Municipality of Clarington. The assessment was completed in March 2015. From Liberty Street in Clarington to Highway 35/115, Highway 401 will be widened from six to eight lanes.

To support this widening, all of the original overpasses dating back in the 1940s and 1950s built through Whitby and Oshawa will be replaced with new overpasses as part of modern highway safety standards and to allow for a future highway widening.

Eastern Ontario

East of Durham, the MTO is planning to widen parts of Highway 401 to six lanes. Two bridges have been widened in advance of an eventual widening to six lanes of the highway including the bridges over the Trent River in Trenton, as well as the Salmon River bridge between Belleville and Napanee. By 2020, the highway was widened to six lanes for 9 km (5.6 mi) through Kingston between exits 611 and 623. Construction began in 2014 to expand the highway to six lanes approximately five kilometres (3.1 mi) east of exit 474 in Cobourg. As of 2020, there are further studies to widen the highway to six lanes east of Cobourg to Colborne, and through Belleville, including replacing the current interchanges with more modern designs.

Services

See also: ONroute

ONroute Cambridge South service station

Highway 401 features 19 ONroute service centres operated under contract from the Ministry of Transportation. They provide a place to park, rest, eat and refuel 24 hours a day. Service centres along Highway 401 were first announced in 1961 following public outcry over the lack of rest stops. The centres were originally leased to and operated by several major gasoline distributors; however, those companies chose not to renew their leases as the terms ended.

In response, the MTO put the operation of the full network of service centres out for tender, resulting in a 50-year lease agreement in 2010 with Host Kilmer Service Centres, a joint venture between hospitality company HMSHost (a subsidiary of Autogrill) and investment company Kilmer van Nostrand.

Seventeen of the centres along Highway 401 have been reconstructed entirely. Two centres rebuilt in the late 1990s, specifically Newcastle and Ingersoll, were not redeveloped at that time. Both of these travel centres are the same design as the Maple Travel Plaza on Highway 400. Work on rebuilding 15 of the 17 service centres began in late 2009 or early 2010. The new service centres, opened in phases beginning in July 2010, feature a Canadian Tire gas station, an HMSHost-operated convenience store known as "The Market", as well as fast food brands such as Tim Hortons, A&W, Pizza Pizza, Extreme Pita, KFC, Taco Bell, Big Smoke Burger and Burger King.

Service centres along Highway 401

Location	Direction(s)	Nearby exits	Status
Tilbury North	Westbound	56, 63	Reopened as of October 1, 2010
Tilbury South	Eastbound
West Lorne	Westbound	137, 149	Reopened as of October 1, 2010
Dutton	Eastbound
Ingersoll	Westbound	222, 230	Will not be redeveloped at this time. Leased by Imperial Oil.
Woodstock	Eastbound		Closed for reconstruction on March 31, 2010; reopened July 2011
Cambridge North	Westbound	286, 295	Closed for reconstruction on September 7, 2011; Cambridge North reopened June 25, 2013; Cambridge South reopened July 23, 2013.
Cambridge South	Eastbound
Mississauga	Eastbound	333, 336	Built 1991 the service centre differed with the 1960s era and late 1990s rebuild. Permanently closed as of September 30, 2006. Building demolished in December 2010 and ramps closed off. Now redeveloped as OPP Mississauga Detachment.
Newcastle	Westbound	440, 448	Will not be redeveloped at this time. Leased by Imperial Oil.
Port Hope	Eastbound	448, 456	Reopened by June 2011
Trenton North	Westbound	509, 522	Reopened as of October 1, 2010
Trenton South	Eastbound		Reopened March 2011
Napanee	Westbound	582, 593	Closed for reconstruction March 31, 2010; reopened June 2011
Odessa	Eastbound	599, 611	Open during 2010–11 reconstruction (while a new structure was built directly west of a now-demolished original facility on same property). New facility opened June 2011
Mallorytown North	Westbound	675	Reopened February 1, 2011
Mallorytown South	Eastbound	685	Reopened June 28, 2012.
Morrisburg	Eastbound	750, 758	Reopened as of October 1, 2010
Ingleside	Westbound	758, 770	Reopened April 2011
Bainsville	Westbound	825	Reopened as of October 1, 2010
Closed

Exit list

The following table lists the major junctions along Highway 401, as noted by the Ministry of Transportation of Ontario. 

Division	Location	km	mi	Exit	Destinations	Notes
Detroit River Canada–US border		0.0	0.0		To I-75 / I-96	Via future connector in Michigan, planned opening in 2024
				Gordie Howe International Bridge, planned opening in 2024
Windsor		2.0	1.2	1	Ojibway Parkway E. C. Row Expressway Detroit via Detroit-Windsor Truck Ferry	Westbound exit and eastbound entrance; western terminus
		3.4	2.1	2	E. C. Row Expressway	Eastbound exit; westbound access will open to connect to Gordie Howe International Bridge
		4.7	2.9	5	Highway 3 (Huron Church Road) – Windsor, Ambassador Bridge, Detroit	Westbound exit and eastbound entrance; former western terminus from June 28 to November 21, 2015
		5.8	3.6	6	Cabana Road West  County Road 6 (Todd Lane) – LaSalle	Eastbound exit and eastbound entrance, westbound entrance from Highway 3 West
		7.1	4.4	7	Highway 3 (Talbot Road) – LaSalle	Westbound exit to Highway 3 West, eastbound exit to Highway 3 East, eastbound entrance from Highway 3 East
		10.1	6.3	10	Highway 3 – Leamington, Windsor  County Road 9 (Howard Ave) – Amherstburg	Former western terminus from 1957 to June 28, 2015
		12.6	7.8	13	Dougall Parkway  – Detroit–Windsor Tunnel, Detroit	Westbound exit and eastbound entrance; formerly Highway 3B/Highway 401A
Essex	Tecumseh	13.4	8.3	14	County Road 46 (to/vers Walker Road) – Windsor, Essex	Formerly Highway 98, access to Windsor International Airport
		20.4	12.7	21	County Road 19 (Manning Road) – Tecumseh
	Lakeshore
		27.5	17.1	28	County Road 25 (Puce Road) – Puce
		33.7	20.9	34	County Road 27 (Belle River Road) – Woodslee, Belle River
		40.0	24.9	40	County Road 31 (French Line Road) – St. Joachim	Formerly known as St. Joachim Road
		47.3	29.4	48	Highway 77 south – Leamington  County Road 35 north (Comber Road) – Stoney Point	Northern terminus of Highway 77
		55.7	34.6	56	County Road 42 – Tilbury	Formerly Highway 2
Chatham-Kent		60.2	37.4	Tilbury Service Centres
		62.8	39.0	63	County Road 2 (Queen's Line)	Formerly Highway 2
		80.9	50.3	81	County Road 27 (Bloomfield Road)
		89.3	55.5	90	Highway 40 north County Road 11 south (Communication Road) – Blenheim	Southern terminus of Highway 40
		101.0	62.8	101	County Road 15 (Kent Bridge Road) – Dresden, Ridgetown
		108.3	67.3	109	County Road 17 / County Road 21 (Victoria Road) – Thamesville, Ridgetown	Formerly Highway 21
		116.2	72.2	117	County Road 20 (Orford Road) – Highgate
Elgin	West Elgin	129.2	80.3	129	County Road 103 (Furnival Road) – Wardsville, Rodney
		137.3	85.3	137	County Road 76 (Graham Road) – West Lorne	Formerly Highway 76
	Dutton/Dunwich	143.8	89.4	Dutton (Eastbound) / West Lorne (Westbound) Service Centres
		148.5	92.3	149	County Road 8 (Currie Road) – Dutton
		157.4	97.8	157	County Road 14 (Iona Road) – Melbourne, Iona
	Southwold
		164.1	102.0	164	County Road 20 (Union Road) – Port Stanley, Shedden
London		176.7	109.8	177	Highway 4 south (Colonel Talbot Road) – St. Thomas	Signed as exits 177A (south) and 177B (north); reconstruction planned, turning the cloverleaf interchange into a parclo
		179.4	111.5	180	Highway 4 north (Wonderland Road)	Construction begun in early 2014, opened November 2015. Highway 4 re-routed along Wonderland Road in 2018.
		183.2	113.8	183	Highway 402 west – Sarnia	Westbound exit and eastbound entrance
		185.9	115.5	186	Wellington Road
		186.8	116.1	187	Exeter Road	Westbound exit, formerly Highway 135 west
		189.1	117.5	189	Highbury Avenue – St. Thomas	Formerly Highway 126
		193.6	120.3	194	Veterans Memorial Parkway	Formerly Highway 100; reconstruction and expansion from a three-way to four-way interchange begun in 2015; access to London International Airport
Middlesex	Thames Centre	195.5	121.5	195	County Road 74 (Westchester Bourne) – Nilestown, Belmont	Formerly Highway 74
		199.3	123.8	199	County Road 32 (Dorchester Road) – Dorchester
		203.0	126.1	203	County Road 73 (Elgin Road) – Aylmer	Formerly Highway 73
		208.5	129.6	208	County Road 30 (Putnam Road) – Putnam, Avon
Oxford	South-West Oxford, Ingersoll	216.0	134.2	216	County Road 10 (Culloden Road)
		218.5	135.8	218	Highway 19 south County Road 119 north (Plank Line) – Tillsonburg
	South-West Oxford	222.2	138.1	222	County Road 6 – Stratford, Embro
		223.2– 224.8	138.7– 139.7	Ingersoll (Westbound) / Woodstock (Eastbound) Service Centres
		229.8	142.8	230	County Road 12 (Sweaburg Road / Mill Street) – Sweaburg
	Woodstock
		231.9	144.1	232	County Road 59 – Delhi	Formerly Highway 59
		235.3	146.2	235	Highway 403 east – Brantford, Hamilton	Eastbound exit and westbound entrance
	Norwich
		236.3	146.8	236	County Road 15 (Towerline Road) – Woodstock
		237.9	147.8	238	County Road 2 – Paris, Woodstock	Formerly Highway 2
	Woodstock
	Blandford-Blenheim	250.1	155.4	250	County Road 29 (Drumbo Road) – Innerkip, Drumbo
Waterloo|Regional Municipality of Waterloo|Waterloo	North Dumfries	267.9	166.5	268	Regional Road 97 (Cedar Creek Road) – Cambridge, Plattsville, Ayr	Signed as exits 268A (east) and 268B (west) eastbound; formerly Highway 97
	Kitchener, Cambridge	275.0	170.9	275	Regional Road 28 (Homer Watson Boulevard / Fountain Street)
		277.9	172.7	278	Highway 8 north – Kitchener, Waterloo Regional Road 8 south – Cambridge	Westbound exit and eastbound entrance only to Highway 8; signed as exit 278A (east) and 278B (west) eastbound
	Cambridge	282.5	175.5	282	Regional Road 24 (Hespeler Road) to Highway 24 south – Brantford
		283.8	176.3	284	Regional Road 36 south (Franklin Boulevard)	Eastbound to southbound exit and northbound to westbound entrance
		286.5	178.0	286	Regional Road 33 (Townline Road) County Road 33 (Townline Road)
Wellington	Puslinch
		289.8	180.1	Cambridge Service Centres
		295.7	183.7	295	Highway 6 north – Guelph	Western end of Highway 6 concurrency
		300.1	186.5	299	Highway 6 south – Hamilton County Road 46 (Brock Road) – Guelph, Hamilton	Eastern end of Highway 6 concurrency
Halton|Regional Municipality of Halton|Halton	Milton	311.9	193.8	312	Regional Road 1 (Guelph Line) – Burlington, Campbellville
		320.1	198.9	320	Regional Road 25 – Acton, Milton	Formerly Highway 25; GO Transit bus stop on eastbound ramp
		323.8	201.2	324	Regional Road 4 (James Snow Parkway)
		328.0	203.8	328	Regional Road 3 (Trafalgar Road) – Oakville, Halton Hills, Georgetown
		330.4	205.3	330	Highway 407ETR	Toll highway; signed as exits 330A (west) and 330B (east) eastbound; no access from westbound Highway 407 to eastbound Highway 401 or westbound Highway 401 to eastbound Highway 407
Peel|Regional Municipality of Peel|Peel	Mississauga	332.7	206.7	333	Regional Road 19 (Winston Churchill Boulevard)	Southern terminus of Regional Road 1 designation
		333.3	207.1	Former Mississauga Info Centre (Eastbound); operated from 1991 to 2006 and demolished in 2010 (Presently the site of the OPP Mississauga Detachment, which opened in September 2020)
		336.1	208.8	336	Regional Road 1 (Mississauga Road / Erin Mills Parkway)	Although signed as both the exit for Mississauga Road and Erin Mills Parkway, Erin Mills Parkway merges with Mississauga Road 1.7 km (1.1 mi) to the south and does not officially reach Highway 401
		337.8	209.9	Western end of collector–express system
		339.6	211.0	340	Mavis Road	Exit opened in 1999.
		341.7	212.3	342	Hurontario Street	Formerly Highway 10; westbound exit from both collectors and express
					Whittle Road	Eastbound exit
		344.5– 345.4	214.1– 214.6	344	Highway 403 west – Hamilton  Highway 410 north – Brampton	Former partial interchange; full access to/from Highways 403 and 410 after new ramps from eastbound Highway 401 to westbound (south) Highway 403 and from eastbound (north) 403 to westbound 401 were opened in 2018
		347.6	216.0	346	Regional Road 4 (Dixie Road)
		350.3	217.7	Eastern end of collector–express system
		350.3– 351.1	217.7– 218.2	348	Highway 427 / Renforth Drive – Toronto Pearson International Airport, Downtown Toronto	Exit 348 (eastbound exit and westbound entrance), exit 350 (eastbound exit and westbound entrance), exit 351 (westbound exit and eastbound entrance) and exit 352 (westbound exit and eastbound entrance)
Toronto
				350	Eglinton Avenue
				351	Carlingview Drive
				352	Highway 427 south
		353.5	219.7	354	Dixon Road / Martin Grove Road	No access from southbound Martin Grove to eastbound Highway 401; No access from eastbound Highway 401 to Martin Grove
		355.4	220.8	355	Highway 409 – Toronto Pearson International Airport Belfield Road / Kipling Avenue	Westbound exit and eastbound entrance
		355.4	220.8	Western end of collector–express system
		356.0	221.2	356	Islington Avenue
		357.4	222.1	357	Weston Road
		358.9	223.0	359	Highway 400 north (south to Black Creek Drive) – Barrie	Eastbound express access to Highway 400
		360.5	224.0	360	Jane Street	Ramps removed; access to Jane Street via Black Creek Drive
		362.0	224.9	362	Keele Street
		364.0	226.2	364	Dufferin Street, Yorkdale Road	Eastbound exit and westbound entrance
		364.8	226.7	365	Allen Road, Yorkdale Road	Westbound exit is a left-hand exit from collector lanes, and right-hand exit from express lanes; westbound access to Dufferin Street via Yorkdale Road
		366.2	227.5	366	Bathurst Street	Westbound exit and eastbound entrance (access only from northbound Bathurst Street); westbound entrance and eastbound exit ramps removed; westbound exits to Wilson Avenue, about 200m west of Bathurst Street
		367.3	228.2	367	Avenue Road	Formerly Highway 11A
		368	229	–	Yonge Boulevard
		369.0	229.3	369	Yonge Street	Formerly Highway 11
		371.0	230.5	371	Bayview Avenue
		372.9	231.7	373	Leslie Street
		374.9	233.0	375	Highway 404 north – Newmarket Don Valley Parkway – Downtown Toronto	From eastbound Highway 401, access to Sheppard Avenue via northbound Highway 404 from 401 collector lanes only
		376.3	233.8	376	Victoria Park Avenue
		377.6	234.6	378	Warden Avenue
		379.2	235.6	379	Kennedy Road
		380.8	236.6	380	Brimley Road south, Progress Avenue	Eastbound exit and westbound entrance from northbound Brimley Road; exit opened February 18, 1988
		381.6	237.1	381	McCowan Road
					Corporate Drive	Eastbound entrance
		383.2	238.1	383	Markham Road	Formerly Highway 48
					Progress Avenue	Eastbound entrance
		385.0	239.2	385	Neilson Road	Exit opened in 1983
		386.5	240.2	387	Morningside Avenue
		389.0	241.7	389	Meadowvale Road
		390.3	242.5	390	Kingston Road, "Highway 2A", Sheppard Avenue (westbound), Port Union Road (eastbound)	Kingston Road was formerly Highway 2; Highway 2A was downloaded to the City of Toronto; Signed as exit 392 westbound
Durham|Regional Municipality of Durham|Durham	Pickering	394.0	244.8	394	Regional Road 38 (Whites Road)	Exit opened in 1983
		396.6	246.4	397	Regional Road 29 (Liverpool Road)	Westbound exit and entrance
		398.3	247.5	399	Regional Road 1 (Brock Road)	Exit opened September 11, 1974, replacing the full-access interchange at Liverpool Road
		398.3	247.5	Eastern end of collector–express system
	Ajax	400.3	248.7	400	Church Street	Removed, exit replaced with Westney Road interchange (exit 401) in 1986
		401.3	249.4	401	Regional Road 31 (Westney Road)	Replaced exit 400 (Church Street) in 1986 as part of Go Transit expansion east of Pickering
		402.5	250.1	403	Regional Road 44 (Harwood Avenue)	Removed, exit replaced with Salem Road interchange (exit 404) in 2003
		404.3	251.2	404	Regional Road 41 (Salem Road)	Replaced exit 403 (Harwood Avenue) in December 2003
	Whitby/Ajax boundary	406.9	252.8	406	Regional Road 23 (Lakeridge Road)	Westbound entry and eastbound exit; construction begun in 2013, completed Spring 2016
	Whitby	407.7	253.3	408	Road 412 north – Whitby	Toll highway; construction begun in 2013, completed June 20, 2016
		409.6	254.5	410	Regional Road 46 (Brock Street)	Formerly Highway 12; Durham Regional Highway 12 begins at Regional Road 28 (Rossland Road) to the north of the interchange, and it runs northward to just south of Highway 407 at the current southern end of Road 12
		412.1	256.1	412	Regional Road 26 (Thickson Road)
	Oshawa	415.2	258.0	415	Regional Road 53 (Stevenson Road)	Replaced exit 416 (Park Road) in 2009
		415.8	258.4	416	Regional Road 54 (Park Road)	Removed, exit replaced with nearby Stevenson Road interchange (exit 415) in 2009
		417.6	259.5	417	Regional Road 2 (Simcoe Street)	Westbound exit via exit 418
		418.5	260.0	418	Regional Road 16 (Ritson Road)
		419.4	260.6	419	Regional Road 22 / Regional Road 33 (Bloor Street / Harmony Road)	Access to Regional Road 56/Farewell Street
	Clarington	425.4	264.3	425	Regional Road 34 (Courtice Road) – Courtice
		426.5	265.0	426	Road 418 north – Clarington	Toll highway; construction begun in 2016, Opened on December 9, 2019
		428.4	266.2	428	Holt Road (Darlington Nuclear Generating Station)	Formerly eastbound exit and westbound entrance; converted into a full interchange, opened June 2016
		431.3	268.0	431	Regional Road 57 (Bowmanville Avenue) – Bowmanville	Formerly Waverley Road
		432.4	268.7	432	Regional Road 14 (Liberty Street) – Bowmanville, Port Darlington
		435.2	270.4	435	Bennett Road
		436.3	271.1	436	Highway 35 / Highway 115 – Peterborough, Orono, Lindsay
		440.1	273.5	440	Regional Road 17 (Mill Street) – Newcastle, Bond Head
		443.8	275.8	Newcastle Service Centre (Westbound)
		448.1	278.4	448	Regional Road 18 (Newtonville Road) – Newtonville
Northumberland	Port Hope	452.9	281.4	Port Hope Service Centre (Eastbound)
		456.6	283.7	456	Wesleyville Road
		461.4	286.7	461	County Road 2 (Toronto Street) – Welcome	Formerly Highway 2
		464.8	288.8	464	County Road 28 (Ontario Street) – Peterborough, Bewdley	Formerly Highway 28
	Cobourg, Hamilton	472.6	293.7	472	County Road 18 (Burnham Street) – Gores Landing
		474.5	294.8	474	County Road 45 (Baltimore Road) – Norwood, Baltimore	Formerly Highway 45; signed as exits 474A and 474B eastbound
	Alnwick/Haldimand	487.0	302.6	487	County Road 23 (Lyle Street) – Centreton, Grafton	Formerly Aird Street
	Cramahe	497.2	308.9	497	County Road 25 (Percy Street / Big Apple Drive) – Colborne, Castleton
	Brighton	509.7	316.7	509	County Road 30 – Brighton, Campbellford	Formerly Highway 30
Hastings	Quinte West	519.5	322.8	Trenton Service Centres
		522.2	324.5	522	Road 40 (Wooler Road) – Trenton
		525.4	326.5	525	Road 33 – Trenton, Frankford, Batawa	Formerly Highway 33
		526.5	327.2	526	Road 4 (Glen Miller Road) – Trenton, CFB Trenton
		538.5	334.6	538	Road 1 (Wallbridge-Loyalist Road) – Stirling
	Belleville
		542.7	337.2	543	Highway 62 – Marmora, Madoc to County Road 14	Signed as exits 543A (south) and 543B (north); formerly Highway 14
		543.2	337.5	544	Highway 37 – Tweed
	Tyendinaga	555.7	345.3	556	County Road 7 (Shannonville Road) – Shannonville, Tyendinaga Mohawk Territory
		566.4	351.9	566	Highway 49 County Road 15 (Marysville Road) – Picton, Deseronto, Tyendinaga Mohawk Territory
		570.5	354.5	570	County Road 10 (Deseronto Road) – Deseronto
Lennox and Addington	Greater Napanee
		578.8	359.6	579	County Road 41 – Napanee, Kaladar	Formerly Highway 41; signed as exits 579A and 579B westbound
		582.1	361.7	582	County Road 5 (Palace Road) – Napanee, Newburgh
	Loyalist	591.9	367.8	Camden East Service Centre (Westbound)
		593.4	368.7	593	County Road 4 (Camden East Road) – Millhaven, Camden East	Formerly Highway 133
		598.8	372.1	599	County Road 6 (Wilton Road) – Yarker, Amherstview, Odessa
Kingston		603.5	375.0	Odessa Service Centre (Eastbound)
		610.8	379.5	611	Road 38 – Harrowsmith, Sharbot Lake	Formerly Highway 38
		613.0	380.9	613	Road 9 (Sydenham Road), Sydenham
		615.3	382.3	615	Sir John A. Macdonald Boulevard
		617.0	383.4	617	Road 10 (Division Street) – Westport
		619.0	384.6	619	Road 11 (Montreal Street) – Battersea
		623.0	387.1	623	Highway 15 – Smiths Falls, Ottawa
		631.9	392.6	632	Road 16 (Joyceville Road) – Joyceville
Leeds and Grenville	Gananoque, Leeds and the Thousand Islands	645.1	400.8	645	County Road 32 – Crosby	Formerly Highway 32
		646.7	401.8	647	Thousand Islands Parkway – Ivy Lea, Rockport	Eastbound exit and westbound entrance
	Leeds and the Thousand Islands
		647.9	402.6	648	Highway 2 west – Gananoque County Road 2 east	Eastbound via exit 647
		658.8	409.4	659	County Road 3 (Reynolds Road) – Ivy Lea, Lansdowne, Rockport
		661.0	410.7	661	Highway 137 to I-81 south – Hill Island, Thousand Islands Bridge, Watertown
	Front of Yonge	675.5	419.7	675	County Road 5 (Mallorytown Road) – Mallorytown, Athens, Rockport
		667.3– 671.8	414.6– 417.4	Mallorytown Service Centres
	Elizabethtown-Kitley
		684.7	425.5	685	Thousand Islands Parkway	Westbound exit and eastbound entrance
		686.7	426.7	687	County Road 2 – Brockville	Formerly Highway 2
	Brockville	696.2	432.6	696	County Road 29 – Brockville, Smiths Falls	Formerly Highway 29 / Highway 42
		698.0	433.7	698	County Road 6 (North Augusta Road) – Brockville, North Augusta
	Augusta	704.8	437.9	705	County Road 15 (Maitland Road) – Merrickville, Maitland
	Prescott	716.2	445.0	716	County Road 18 (Edward Street) – Prescott, Domville
	Edwardsburgh/Cardinal
		720.1	447.4	721A	Highway 416 north – Ottawa, Kemptville	Eastbound exit and westbound entrance; signed as exit 721 eastbound
		721.2	448.1	721B	Highway 16 – Kemptville, Johnstown, Ogdensburg-Prescott International Bridge NY 812 to NY 37 – Ogdensburg	Signed as exit 721 westbound; NY 812 unsigned
		730.0	453.6	730	County Road 22 (Shanly Road) – Cardinal
Stormont, Dundas and Glengarry	South Dundas	737.8	458.4	738	County Road 1 (Carman Road) – Iroquois
		750.2	466.2	750	County Road 31 – Ottawa, Morrisburg, Winchester	Formerly Highway 31
		756.4	470.0	Morrisburg Service Centre (Eastbound)
		758.2	471.1	758	Upper Canada Road
		761.4	473.1	Ingleside Service Centre (Westbound)
	South Stormont	769.5	478.1	770	County Road 14 (Dickinson Drive) – Ingleside
		777.8	483.3	778	County Road 35 (Moulinette Road) – Long Sault
		786.4	488.6	786	County Road 33 (Power Dam Drive)	Eastbound exit and westbound entrance
	Cornwall	789.5	490.6	789	Highway 138 (Brookdale Avenue) – Ottawa, Hawkesbury, Three Nations Crossing to Massena, New York
		791.8	492.0	792	McConnell Avenue
		796.1	494.7	796	County Road 44 (Boundary Road)
	South Glengarry
		804.6	500.0	804	County Road 27 (Summerstown Road) – Summerstown
		813.8	505.7	814	County Road 2 / County Road 34 – Lancaster, Alexandria, Hawkesbury	Formerly Highway 2 south / Highway 34 north
		825.4	512.9	825	County Road 23 (4th Line Road, Curry Hill Road)
		827.2	514.0	Bainsville Service Centre (Westbound)
Ontario–Quebec border		828.0	514.5		A-20 east – Montreal	Highway 401 continues as A-20
1.000 mi = 1.609 km; 1.000 km = 0.621 mi       Closed/former       Incomplete access       Unopened

See also

• Heavy Rescue: 401—a documentary/reality series on Discovery Channel showcasing the operations of heavy rescue and recovery towing businesses along the highway and nearby roads.
• Southern Ontario Transportation

External links

Wikimedia Commons has media related to: Ontario Highway 401 or Highway of Heroes

Official websites

• Ministry of Transportation of Ontario
• The Rt. Honourable Herb Gray Parkway (Windsor-Essex Parkway) web site
• Live COMPASS Traffic Cameras

Photos and additional information

• Highway 401 at OntHighways
• Highway 401 at vintagekingshighways.com