I came upon this from wikipedia, I think it gives a good overview of the whole history of the larger issue:
Street naming
Most streets in Montreal do not change name throughout their course, respecting their grid axis. Streets such as Saint Lawrence Boulevard, Papineau Ave., De Lorimier Ave. and Pie-IX Blvd. have a foot in both rivers, and some streets re-commence despite gaps or interruptions. There are a few notable exceptions which continue for historical reasons. A few north-south streets which begin in Old Montreal change name at Sainte-Antoine Street (formerly Craig Street), site of the former city wall (Saint-Pierre → Bleury, Bonsecours → Saint-Denis). Only one street changes name many times: McGill Street → Square-Victoria Street → Beaver Hall Hill → Frère-André Place → Phillips Place → Phillips Square → Aylmer St.
According to the rules of the Commission de toponymie du Québec, the French-language form of street names is the only official one, and is to be used in all languages: e.g. chemin de la Côte-des-Neiges; rue Sainte-Catherine; côte du Beaver Hall. Most English speakers, however, use English generic equivalents such as "street" or "road", as do English-language media such as the Montreal Gazette. Officially bilingual boroughs have the right to use such names in official contexts, such as on street signs. In the past, a number of streets had both English and French names, such as "avenue du Parc" or "Park Avenue", "rue de la Montagne" or "Mountain Street", "rue Saint-Jacques" or "Saint James Street". Some of these names are still in common colloquial use in English, and perpetuated by the tourism industry. Many streets incorporate an English specific name into French, such as "chemin Queen Mary", "rue University", "avenue McGill College". There are also a few cases where two names are official, such as "chemin du Bord-du-Lac/Lakeshore Road".
In English, the pre-Francization names are still commonly used, thus, although only the French is 'official', in English one often hears names such as Park Avenue, Mountain Street, Saint Lawrence Boulevard, Pine Avenue, Saint John's Boulevard etc. Canada Post accepts the French specific with English generic, as in "de la Montagne Street" or "du Parc Avenue", although many such forms are never used in speaking. Another anomaly that typifies this kind of mixed heritage and history is René Lévesque Boulevard. Once called "Dorchester Boulevard" in its entirety, this long east-west street was renamed for Quebec former nationalist Prime Minister René Lévesque, except for sections that run through the very Anglophone city of Westmount. However, the entire street is still sometimes referred to as "Dorchester."
It is useful to note that, in Montreal as in other cities, the generic is usually omitted in either language, so one would simply talk of Park (or Du Parc), Mountain (or De la Montagne), Saint Lawrence (or Saint Laurent), University, McGill College, Doctor Penfield, or Fairmount. This is mainly because a specific is almost never given to two streets. If duplication exists, they are always in different boroughs or towns and are retained for historical reasons. For example, Montreal's present 19 boroughs have 6 streets named "Victoria" (2 streets, 2 avenues, one court, and one square), and 9 more in on- or off-island suburbs. In recent years Montréal and most of its suburbs have dispensed entirely with such generic and linguistically fraught terms on their street signage.
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