In fact, this problem is so well known that it gets its own bit on Wikipedia. The “geography of Montreal” page explains that it is, in fact, all the fault of a river:
One quirk of common Montreal parlance is that directions (north, south, east, and west) along the street grid are sharply skewed relative to the actual compass directions. The St. Lawrence River is taken as flowing west to east (even though it flows north or northeast past the island), so that directions along streets parallel to the river are referred to as “west” and “east,” and those along streets perpendicular to the river, “north” and “south.”
But this is really only half an answer at best, since it serves mainly to make you wonder why someone decided the river flows east when it’s very clearly flowing north. “Because it’s heading for the Atlantic, which is roughly east,” I suppose.
Except that’s not an explanation at all is it? The Seine goes in all sorts of weird directions on its way around Paris. If the city authorities decreed the left bank always counted as west just because the sea was roughly north, the compass needle would be spinning like a bloody top.
It gets worse:
In much of Montreal, “north” is actually northwest, and in some areas such as Verdun and Pointe-aux-Trembles it is actually due west. “Montreal directions” are used in naming street addresses and describing bus routes, among other things. As a result of this discrepancy, Montreal has been called “the only city where the sun sets in the north.”
And nobody thought, at the point where the sun is literally setting in the direction that everyone thinks is north, that maybe they’d buggered up this whole geography thing?
One weird side effect of all this: if the St Laurence is assumed to be flowing to the east (which is actually north), then the Victoria Bridge, which connects the city to the suburb of Saint-Lambert, must be running from north to south (even though it’s is actually west to east). That means that the Saint-Lambert end must be the southern edge of the bridge.
Check out the state of this explanatory note on its own Wikipedia page:
Directions are according to traditional Montreal map where downtown (example, rue Sherbrooke) is east-west, with Mont-Royal to the north and the river to the south. “North” on the Victoria bridge is actually south-west.This article is from the CityMetric archive: some formatting and images may not be present.