Detroit
I think that would be Detriot, Michigan if you look closely at the map.
Anchorage, Alaska; the last part of the road into Canada is south east.
Detroit is one. When I fly from Milwaukee to Niagara Falls I end up slightly south and east. 92 degree heading
Detroit, Michigan, is actually situated north of Windsor, Ontario. Therefore, you can drive south from Detroit, either across the bridge or through the tunnel, to get to Windsor, Ontario, Canada. That, however, is not the only example of driving south from the US to Canada. There are at least two examples of a highway running south from Alaska into Canada. In addition, it appears there may be a couple of examples of a road running in a southeasterly direction between Maine and New Brunswick.
Highways link cities - there are no major cities in the northern part of Canada
Mackenzie River
Hudson Bay is the answer to this problem.
Detroit-Buffalo
Canadian Rockies are the major mountain range in the western Canada. The Rockies are a 3000 miles long range with Northern most edge in British Columbia, Canada and southern edge in the Northern New Mexico, USA.
In Canada there are many colleges a person can enter that will accept 3 AS levels. Most of the major colleges, however, will not accept only 3 AS levels.
Most colleges in Canada require at least a 3 AS level for someone to be able to enter. The major colleges require higher than 3 AS levels.