Canadian highways that retain the numbers of American ones across the border

[KCRoadFan]

I know that in Canada, there's no equivalent to the "US highway" system - the role of highway numbering is exclusively the domain of the provinces. The closest equivalents to a "national highway" would be the section of the Trans-Canada Highway through the western provinces of British Columbia, Alberta, Saskatchewan, and Manitoba, as well as the Yellowhead Route through the same four provinces -  but even with those roads, my understanding is that both roads are still technically considered a series of separate provincial highways that just so happen to have been given the same number by each province (1 and 16, respectively) for purposes of coordination.

That being said, I have noticed that some provinces do allude to US highways, in the sense that they retain the numbers of the roads that cross the border. This seems rather common in BC, especially - BC 93, BC 95, and BC 97 are all northern continuations of the US highways of the same number, while BC 99 - which I-5 connects to - is a throwback to US 99, which was decommissioned after I-5 was built.

Aside from BC, Manitoba does this some as well - US 83 becomes MB 83, and while MB 75 - the road connecting Winnipeg to the border - continues as I-29 rather that US 75, the road that US 75 becomes across the border does eventually link up to MB 75. One province over in Ontario, MN 61 - the road along the north shore of Lake Superior in Minnesota - continues on towards Thunder Bay as ON 61, and further east, in New Brunswick, NB 95 is the designation for the road continuing past the northern terminus of I-95 in Maine, eventually meeting NB 2 - the main highway of that province.

Besides what I already mentioned, what other examples might there be of Canadian provincial highways that retain the numbers of their American counterparts after crossing the border - whether they be US highways, state highways, or even interstates? I'm sure there's at least a handful of them.

[LilianaUwU]

The opposite happens with many Québec highways, with QC 139, 141, 147, 225, 235, 243, 253 having Vermont counterparts. Also, 1 and 16 are far from the only number given to the TCH, even though they are the most common numbers for the highway.

[Bruce]

At one point, BC numbered all of their border-crossing highways to conform with (or get close to) their WA counterparts. WA then renumbered the highways, so the BC ones are relics of the past system.

BC 99 - I-5 (former US 99)
BC 15 - SR 543 (former PSH 1 branch)
BC 13 - SR 539 (former SSH 1B, which looks like a 13)
BC 11 - SR 9 (former SSH 1A, the first letter branch and first odd double-digit)
BC 97 - US 97
BC 41 - SR 21 (former SSH 4A)
BC 395 - US 395
BC 22 - SR 25 (former PSH 22)
BC 22A - former SR 251 (former SSH 22A)
BC 6 - SR 31 (former PSH 6)

[KCRoadFan]

At one point, BC numbered all of their border-crossing highways to conform with (or get close to) their WA counterparts. WA then renumbered the highways, so the BC ones are relics of the past system.

BC 99 - I-5 (former US 99)
BC 15 - SR 543 (former PSH 1 branch)
BC 13 - SR 539 (former SSH 1B, which looks like a 13)
BC 11 - SR 9 (former SSH 1A, the first letter branch and first odd double-digit)
BC 97 - US 97
BC 41 - SR 21 (former SSH 4A)
BC 395 - US 395
BC 22 - SR 25 (former PSH 22)
BC 22A - former SR 251 (former SSH 22A)
BC 6 - SR 31 (former PSH 6)

What do PSH and SSH mean? Primary and Secondary State Highway, I would assume - right?

[Alps]

The opposite happens with many Québec highways, with QC 139, 141, 147, 225, 235, 243, 253 having Vermont counterparts. Also, 1 and 16 are far from the only number given to the TCH, even though they are the most common numbers for the highway.

Pre-1975ish, Quebec used US Highway numbers for its routes - 9, 7, 5 come immediately to mind

[Ted$8roadFan]

I-95 in Houlton, ME becomes NB-95 after crossing the international border into New Brunswick.

[Amaury]

What do PSH and SSH mean? Primary and Secondary State Highway, I would assume - right?

Correct.

[vdeane]

The opposite happens with many Québec highways, with QC 139, 141, 147, 225, 235, 243, 253 having Vermont counterparts. Also, 1 and 16 are far from the only number given to the TCH, even though they are the most common numbers for the highway.

Pre-1975ish, Quebec used US Highway numbers for its routes - 9, 7, 5 come immediately to mind

They also were part of a former example of cross-jurisdiction numbering coordination in Canada: the former ON/QC/NB/NS 2.  Then Nova Scotia truncated NS 2, Québec renumbered QC 2 into multiple other routes, and Ontario downloaded most of ON 2, leaving NB 2/TCH 2 as the primary remnant.

[dmuzika]

Not a numerical match, but US-85 becomes SK-35; the '8' and '3' look similar.

[dmuzika]

Don't forget the former (MB) PTH 29, the northern extension of I-29 and traveled a whole 500m (1/3 mi) before ending at PTH 75. When the PTH 75/US 75 connection was closed, PTH 75 took over PTH 29.

[7/8]

In addition to MN/ON 61 mentioned in the OP, ON 71 is a continuation of US 71 (at Fort Frances/International Falls)

ON 11 and MN 11 run parallel on each side of the Rainy River (a different scenario but still neat).

[cwf1701]

And before the numbering of Fort Street in Detroit as M-85 in 1999, M-3 ended just blocks from the Ambassador Bridge (at I-75 and Clark), The Ambassador Bridge is the western endpoint of Ontario Highway 3.

[Alps]

Don't forget the former (MB) PTH 29, the northern extension of I-29 and traveled a whole 500m (1/3 mi) before ending at PTH 75. When the PTH 75/US 75 connection was closed, PTH 75 took over PTH 29.

Ah, so the twisting south end of MB 200 took that over. When was that?

[dmuzika]

Don't forget the former (MB) PTH 29, the northern extension of I-29 and traveled a whole 500m (1/3 mi) before ending at PTH 75. When the PTH 75/US 75 connection was closed, PTH 75 took over PTH 29.

Ah, so the twisting south end of MB 200 took that over. When was that?

Yes, a from what I can tell a small section was cosigned as PTH 75/PR 200 between 4 lane highway and Emerson. According to Wikipedia, Canada and the U.S. closed their respective crossings at US 75 in 2003 and 2006 respectively, so I'm guessing the redesignation of PTH 29 happened around the same time.

As a side note, if you look at the map, US 75 follows the east side the Red River of the North, while US 81 follows the west side. As PTH 75 also follows the west side of the river, technically it should have been PTH 81 instead? I do find it interesting that with BC and Manitoba following US route numbering, they never adopted Interstate numbering even though the numbering would have happened relatively around the same time. To the best of my knowledge, I think NB 95 is the only northern continuation of an Interstate number. BC 5 and PTH (MB) 29 to Vancouver and Winnipeg respectively would probably make more sense.

I don't know as much about I-29/PTH 75, but when you consider the timelines I-5/BC 99, it could have happened. BC 99 originally followed King George Hwy and Kingsway between the U.S. border and Vancouver (known as BC 99A from 1973-2006, some maps still show it). The Vancouver-Blaine Freeway (present-day BC 99) was built in 1959-1962, and was designated as BC 499 from 1964-1973 before taking on its current number. At the same time, I-5 opened in the Blaine area in 1963-65, but one can assume that the I-5 designation was known before then.

I recognize BC 5 is a long distance N-S highway in the interior, but BC had already renumbered sections to align with US highways. Its original alignment south of Kamloops went through Kelowna and Osoyoos, but in 1953 it was renumbered along with other routes in to BC 97, with the Kamloops-Merritt-Princeton section (present-day BC 5A) taking on the BC 5. With BC being in a time period where they were willing to renumber highways to align with neighboring jurisdictions (for example, BC 95 used to be BC 4) and the Coquihalla Highway being 20 years from fruition, theoretically BC 5 could have been renumbered to something else to allow for the '5' designation to be used as the northern extension of I-5.

The same could apply to Manitoba. TCH 16, MB 26, and MB 44 used to be part of MB 4, but were renumbered at various times. MB 4 became MB (later TCH) 16 in the mid-1970s to allow for the '16' designation to be continuous along the Yellowhead Hwy, showing that Manitoba did have an appetite from renumbering long distance highways, so renumbering MB 75 to MB 29 to align with I-29 theoretically could have happened.

[mgk920]

I-95 become NB 95 at the border.

Mike