Is there a street index for the larger cities in the 1921 Canadian census?
(When I first asked this question, the 1921 census (on Ancestry) was images only, with no name index. Although a name index now exists, a street index is still useful, especially to find known addresses where the name may have been mistranscribed.)
A city like Toronto is divided into districts (north, west etc) and then by 50-100 subdistricts, each of maybe five street sections and twenty images.
Many of the subdistricts have a full list of the parts of the streets in the polling subdivision they cover:
Sub-District 48 - Ward 3 Polling Subdivision no. 80. Comprising Charles Street, both sides, from Church to Jarvis Street; Hayden Street, both sides, from Church Street to east end; Bloor Street, south side, from Church toJrvis Street; Church Street, both sides, from Isabella to Bloor Street, Jarvis Street, west side, from Isabella to Bloor Street.
If a subdivision has more than one polling subdivision in it, there is no description of the streets included. This may be something that is being worked on, to add later.
I was able to copy and paste the descriptions for several districts of Toronto and find the street I wanted by searching the resulting text. Luckily, the people I looked for hadn't moved since their last known address in 1917, were in a subdistrict where the streets were listed, and were in a short street.
But it would be easier if there was a simple index (street, or section of street, giving district and subdistrict). Does such a thing exist? Even better if it includes the streets that are currently missing from the Ancestry listings (the cases where there is more than one polling district in a subdivision).
Drawing boxes on a map from the subdivision descripions doesn't help, because (in Toronto at least) each street segment in a subdivision is named (there are no further named streets within the area, so nothing else to find). I've drawn Toronto Centre, ward 3, subdistrict 48 (described above), using geojson.io on a modern day map of Toronto, and published it on gist (and now also embedded an image below:).
Note it's not really a box, just a walking route, with only one side of some streets, both sides of others. All the street segments are listed in the description. Looking at other cities, most like Montreal and Vancouver don't have any street descriptions at all, and some like London ONT do have bounding boxes in the description, for that latter case drawing on a map would help.
Using directories to find the ward does really help in a big city, but in the case of Toronto Centre for example there are perhaps 40 subdistricts in a ward, so up to 800 images.
What's needed is a source for the street listings in the cases where Ancestry doesn't list them (usually because it consists of multiple polling subdivisions, see Toronto North for many cases like this). If that information was available, a simple text file search is enough to locate all the segments of a street.
It would also be possible to generate an index from these descriptions, there are typos ("toJrvis") and inconsistent punctuation which make it tricky but using the "sides", "from" and "to" words could get a maybe 90% good-enough index. But it's still working from partial data.
(further update) The 1895 electoral maps at LAC may help narrow down the search for a place if the names are unfamiliar (and unchanged by 1921), and the parlimentary ridings history will give the actual boundaries and a history of the changes.