[Tagging] navigational aid relation

[Minh Nguyen]

Vào lúc 21:59 2023-06-16, Volker Schmidt đã viết:
> When trying to reach a destination that is defined by a complete address 
> (city, street name, house number or name) is that the last meters of the 
> route are, potentially,  much different for a 
> ciclist/pedestrian/car-driver/delivery-van/ambulance/...
> One of the many problems is that we would need for any given address a 
> navigation aid for each of the potential means of transport.
> 
> I have come across one aspect of this when I noticed that Amazon 
> Logistics staff systematically changed access tags on driveways around 
> here from "private" to "yes" (or similar).
> 
> Micromapping correctly the last meters for all the different means of 
> transport is the correct theoretical solution. But is it practical ?
> 
> Navigation aid?
> In Italy the house numbers are assigned to the pedestrian entrance point 
> for the house/business/shop/airport/...

You're quite fortunate that the meaning of an address is unambiguous in 
Italy. At least you can be sure that a pedestrian route will lead to the 
main entrance, even if other modes aren't as well-served. Each country 
has different addressing standards, so what may be sufficient in one 
country might be insufficient in another.

Here in the U.S., the meaning of an address depends on who's using it. 
To the tax authorities, it refers to the whole parcel. To emergency 
responders, it's either the building or the beginning of the driveway. 
To the postal service, it's the mailbox, which can be at the door, at 
the street curb, or even at the neighborhood entrance.

Mappers here generally treat the address as an attribute of a building, 
POI, or something else. [1] So the address point's coordinates don't 
necessarily have any relation to where you would navigate to. But 
addr:street is usually either the name of the street that the building 
faces, or the name of the street that the letter carrier uses to get to 
the mailbox (wherever it is). So at least we know that street is more 
related to the feature than the other nearby streets.

For the majority of cases, that assumption is a good one for navigation, 
but not always. For example, in the suburbs, a house at a street corner 
often has a mailbox at the curb along one street (hence addr:street) -- 
but to get to the front entrance, you use a walkway from a different 
street. To illustrate the point, these examples are fully micromapped 
with mailboxes, entrances, driveways, and walkways:

Mailbox on one street, car and pedestrian entrances on another:
https://www.openstreetmap.org/way/37018678

Mailbox and pedestrian entrance on one street, car entrance on another:
https://www.openstreetmap.org/way/38064995
https://www.openstreetmap.org/way/34618091

Mailbox and car entrance on one street, pedestrian entrance on another:
https://www.openstreetmap.org/way/37018646

Mailbox on one street, car and pedestrian entrances accessible from 
either street:
https://www.openstreetmap.org/way/34618083

Everything on one street, but addr:street names a different street. 
(What's a rule without an exception?)
https://www.openstreetmap.org/way/32602856
https://www.openstreetmap.org/way/34618143

These are trivial cases where getting to the wrong street isn't much of 
a problem for most people, though enough of this misdirection could 
throw a delivery person off schedule. If the style of micromapping in 
these examples becomes widespread enough, then the addr:street-based 
heuristic becomes unnecessary. But that's a herculean task, even bigger 
than mapping all the addresses in the first place.

> Take an address in a pedestrian area within a limited-access zone in my 
> city.
> Take car access. During the night the car access for drop-down is 
> somewhere in walking distance outside the pedestrian area, but within 
> the limited-traffic zone (which is not active at night). During the day 
> it is most likely a park-and-ride location outside the city centre.

This is another good reason why I'd advocate for objectively 
micromapping features that data consumers (whether routers or geocoders) 
could recognize as navigable points or not, depending on the situation. 
For the difficult, indescribable cases, there's already a catch-all site 
relation type.

-- 
minh at nguyen.cincinnati.oh.us