[Talk-us] Directional Prefix/Postfix Proposal

Alan Mintz Alan_Mintz+OSM at Earthlink.Net
Mon Aug 2 21:24:45 BST 2010

At 2010-07-31 18:54, Kevin Atkinson wrote:

>Since someone objected to my proposed changes to Salt Lake City, I am 
>going to go ahead and give my proposal for how I think directional 
>prefixes should be handled.  I am going to stay out of the debate on 
>street name abbreviations and focus on just the directional prefix/postfix 
>parts.  I want to come an agreement on talk-us, and then would like to 
>make it an official standard (at least in the U.S.).
>A full street address included more than just a Number and a Street, it 
>also includes a directional prefix.  Vid the kid, gave an excellent 
>overview at http://vidthekid.info/misc/osm-abbr.html.  For example (from 
>his page) in the address:
>   4242 S Champion Ave E
>The 'S' is a directional prefix and the 'E' is the suffix and in:
>   1337 Rainbow Dr SW
>The 'SW' is a directional suffix (really a quadrant suffix).
>I would like to formally propose two things
>   1) An exception to the abbreviation rule for directional indicators
>      with the fully expanded name going into "alt_name"

I think that it would be better to leave the name tag as it is for now, and 
add new tags for the name components. This way, existing code that uses the 
name tag won't break, and can be modified at the developer's discretion to 
work with the new tags if necessary.

>   2) New tags to record the presence of directional indicators in the
>      address.
>I propose an exception to the abbreviation rule be made for directional 
>indicators.  'North, 'South', 'East', and 'West' when a directional 
>indicator (and not part of the street name) shall be abbreviated 'N.', 
>'S.', 'E.', and 'W.' (with a period, will explain why below), and 
>Northeast, Southeast, Northwest, Southwest shall be abbreviated as 'NW', 
>'SW', 'SE', and 'NW' (without any periods).  The fully expanded name may 
>be included in "alt_name".

I don't think the period convention will end up being well-used. In the 
expanded name (where it is used), I'm not sure it matters, since 
consumer-oriented searches generally use just a single query field, and the 
engine has to do the work of handling the various possibilities. If it does 
use separate fields (or parses the query into separate fields), it would 
then use the component tags instead of the expanded name.

>I propose two new tags:
>   name_prefix
>   name_suffix
>If the directional prefix is not part of the name than the appropriate tag 
>shall be used to indicate the need for a directional prefix in an 
>address.  North, South, etc, shall be abbreviated as one of
>   'N' 'S' 'E' 'W', 'NW' 'SW', 'NE', 'SE'
>There is no need for a period here.


>If it is included in the word "included" shall be used instead.  This 
>means the the first word (for a prefix) or the last word (for a suffix) is 
>a directional indicator and shall be left in abbreviated form by name 
>correction bots and the like.
>Some Examples)
>To encode "South 700 East" in Salt Lake City:
>   name = "S. 700 East"
>   name_prefix = "included"
>   alt_name = "South 700 East"

I would use
name = "South 700 East"
name_prefix = "S"
name_prefix_included = yes
name_root = "700"
name_suffix = "E"

name continues to be used for the full expanded name

name_prefix_included indicates that the name_prefix is normally given on 
the signage in front of the name_root, and used in naming a place or giving 
directions verbally.

I don't think the distinction needs to be made between the suffix's 
inclusion in the name or not (at least I can't think of an example in the 
places I know to use them - DC and UT). That is, it is always considered in 
the same way. If that's not the case, name_suffix_included could be used.

>"K Street NW" in Washington DC,
>   name = "K Street NW"
>   name_suffix = "included"
>   alt_name = "K Street Northwest" (would anyone really write this?)

I'd use:

name = "K Street Northwest" (or is it "K Street NorthWest"?)
name_root = "K"
name_type = "St"
name_suffix = "NW"

Note splitting out the type of street into name_type while we're at it.

>   alt_name = "K Street Northwest" (would anyone really write this?)

I agree, but the abbreviation police held their ground last time we tried 
this, so...

Some examples from southern CA:

1. Most places do not include the directional prefix as part of the signed 
name. If it is present, it is thought of more as a suffix to the address. 
It may be shown next to the address range on the signs in that smaller 
font, not in front of the name in larger font.

Current value of name = "North Euclid Avenue"
name = "Euclid Avenue"
name_prefix = "N"
name_root = "Euclid"
name_type = "Ave"

Note that, in many places, TIGER had these prefixes and they were imported 
as part of the name because TIGER made no distiction between this and case 
#2 (below). They were then expanded to the incorrect form "North Euclid 
Ave". In this example, the prefix isn't even really a prefix to the name, 
but instead a suffix to the housenumber, though I'm OK with using the 
name_prefix tag to avoid confusion. An addr:direction tag would be OK 
instead. I look forward to being able to fix these once we settle on the 

2. Some, however, do use the prefix on the signs and in verbal. The 
direction appears in front of the name in the same font:

name = "West 17th Street"
name_prefix = "W"
name_prefix_included = yes
name_root = "17th"
name_type = "St"

3. In Rancho Cucamonga, the Victoria Gardens mall has two major streets 
running through it, named and signed  "North Mainstreet" and "South 
Mainstreet". In this case, "North" and "South", as well as "street", are 
really part of the name root, and not directions or type. This is because 
they are aligned E/W (90 degrees true) and an address-suffix-style 
name_prefix would be E or W on such a street, not N or S, and you would 
expect them to meet at the point where N turns to S, and for the numbering 
to reverse direction at that point, none of which is true:

name = "North Mainstreet"
name_root = "North Mainstreet"

4. In Rancho Cucamonga, directional prefixes are not used at all. There are 
no north/south or east/west inflection points. Addresses increase southward 
and eastward, often through adjoining cities who don't use directions 
either. Thus, we have a lot of 5-digit addresses.

name = "Foothill Boulevard"
name_root = "Foothill"
name_type = "Blvd"

Note that this structure is necessary for example 3, or there would be 
confusion over having two directional prefixes in an address.

5. Similar to #3 is part of Vermont Avenue, a major N/S artery in Los 
Angeles. They installed light-rail tracks down the middle of it and turned 
it into two one-way streets, signed "West Vermont Ave" and "East Vermont Ave".

name = "West Vermont Avenue"
name_root = "West Vermont"
name_type = "Ave"

Alan Mintz <Alan_Mintz+OSM at Earthlink.net>

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