A deep dive into the OSM Wiki for service=driveway, the proposal service=Driveway2 and lack of professionalism by one OSM Wiki administratorPosted by JaLooooNz on 31 August 2021 in English (English).
This diary explores the problems with the OSM Wiki entry for service=driveway, and why is there a need for service=driveway2. In the process, it also describes the headaches encountered while trying find a optimal solution. However, deeply entrenched opinions makes this process untenable.
Need for clear indication of classified service way type
The topic of discussion will need to begin on how OSM tags are designed in an hierarchy, which begins with initial key-value pair of highway=service, followed by classifier tags service=driveway or service=parking_aisle. Note that highway=service without any service=* does not tell the data consumer if this is simply a minor way that is un-classified (not yet assigned a classification type such as parking_aisle or alley or driveway), or if this minor way is an implicit driveway. In general, a data consumer will assume that the way is un-classified, instead of assuming that it is an implicit driveway.
The classifier issue is the first issue present in the service=driveway Wiki entry - that suggests that minor ways linking from major roads to parking_aisles should be tagged as an implicit driveway with no classifier tags.
- This means that data consumers are unable to determine if the way segment is un-classified, or if it is indeed an implicit driveway when such minor service way connected to parking_aisles are encountered..
- Similarly, a user whom just want to quickly add minor service roads but does not perform classification will mean that data consumers cannot identify if such ways are classified or un-classified, and therefore prevents accurate assessment if further classification is required.
Definition of driveway
This leads to the second problem of what is meant by a driveway, and what is the problem with the Wiki entry. The problem lies with the “classical” definition of driveway, which in the early days of OSM defines it as “a short private road that leads from a street to a person’s house or garage”, sourced from the “American” section of Cambridge’s dictionary. Oxford/Lexico US likewise provides a similar definition “a short road leading from a public road to a house or garage”. This was the original argument by some Wiki participants on what is meant by driveway - mainly based on US English dictionary definitions.
Nevertheless, let’s dive into history where driveway was first defined - ironically in the US California Streets and Highway Code (SHC), which first introduces the driveway term in 1971. In this law stature, driveway “means a paved portion of a public street providing an unobstructed passage from the roadway to an offstreet area used for driving, servicing, parking, or otherwise accommodating motor vehicles.” This part here is significant because this definition predates the introduction of UK highway codes, and describes general use of minor ways as driveways. Note that California laws are very influential in the auto-industry, and drives formation of rules across the US and beyond (impacts globally). Moving to UK law statures (remember the part of OSM being of UK origins?), the term driveway is itself not defined in the law statures. This strongly suggests that usage of this term is strongly linked to “American” usage of this term, which is something pushed by members of the OSM US chapter.
We will further focus on the UK definitions of the term, which is likewise defined in Cambridge’s UK definition as “a private area in front of a house or other building onto which you can drive and park your car”, and similarly Oxford/Lexico UK’s definition of “a short road leading from a public road to a house or other building”. Note that in both UK dictionary definitions, it never suggests that driveway only links to residential properties which routing engines should avoid routing through, but instead is a more general definition similar to the California SHC where it is a minor way going to any property (I.e. no destination access to residential as contrast to US definition).
The difference in understanding is also why despite the Wiki proclamations of such “rules”, there are a large group of users whom are still tagging wrongly - being that they follow the UK definitions or the SHC definitions instead of the US definitions that should be more appropriately tagged as service=residential_driveway (which should apply a routing penalty). This incorrect Wiki definition is the second problem of the existing service=driveway page, where the optimal and most generic classifier used in SHC cannot be defined under service=driveway tagging.
Implications to routing
Maybe you may get the implications to routing at this point, but what is meant by service=driveway in the existing Wiki is meant to apply routing penalties such that routing engines do not route through such driveways. However, this is of the mistaken belief that these ways mostly represent destination minor ways whereby most of such ways are of private access to residential buildings. The more correct representation for such ways is the more appropriate service=residential_driveway, to ensure routing penalty is applied to such ways while allowing service=driveway to be routed through at a significantly lower speeds. This is because in most cases, such minor ways are meant to be publicly accessible to gain access to a property, but is not of a major road type such as highway=residential/unclassified which is a major road class.
Implications to “correct tagging” of driveway (using SHC/UK definitions), and proper use of classifier service=driveway
Well, so far so good, but why is there a need to change the current behaviour? Well, other than people tagging using both types of definition, there are often zealous users whom attempt to “correct” such incorrectly tagged ways such that any classifiers such as service=driveway on minor ways linking to service=parking_aisles are removed.
In essence, useful information detailing the minor way type is removed to an un-classified state, leaving the data consumer left guessing if this is an implicit driveway, an un-classified driveway or a residential_driveway as in problem (1). When you attempt to stop them from removing such details, such users typically will just refer to the Wiki as the source-of-truth, despite that fact that the Wiki itself is also not authoritative and is simply meant to document tag usage for the goal of harmonising tags used. This causes problems whereby correct tagging by natural language understanding falls prey to differently defined Wiki entries.
The most correct way to resolve this problem is to tweak the Wiki to…
- Remove the restriction whereby ways connecting minor ways to parking_aisles should be tagged without the service=driveway classifier. In general, it should be assumed that highway=service without service=* means that the way is un-classified but of minor way, and highway=service with service=* are correctly classified ways.
- Introduce service=residential_driveway for the purpose of private access and destination driveway to residential properties, which is what Amazon and various entities likes to map. In this way, service=driveway can take on its oldest SHC and UK origins definition which is minor road that is meant for motor vehicles and public access, but does not satisfies other classifications such as service=parking_aisle/alley/e.t.c.
In the absence of such changes, we can only continue to tag the SHC and UK definition of driveway as service=driveway2. However, one will typically still run into zealous mappers whom insist on removing classifier tags such as (1).
Notable Problems when discussing with community
The general sense of trying to have a fruitful discussion with various communities is don’t bother. Despite trying to argue the merits and cons, you will have people insisting on schematic definitions (insisting that US dictionary definitions are correct), insisting that other usages of driveway is wrong, insisting that the definition is local/globally used with consensus reached (and thus dismissing local concerns which actually arise from problems with the Wiki entry), insisting that SHC/UK definitions do not matter, do not recognise the problems faced due to a non-authoritative Wiki entry, and in general dismisses your arguments.
Worse, there is one OSM Wiki administrator exhibiting appalling and un-professional behaviour whom insist that this is a user problem. Not only that, this OSM Wiki administrator had to put in his personal opinion by stating that the solution of documenting tag use in the Wiki is the proposal one of user (and that is me). This is something I am proud of, because we are following the process to document tags use instead of trying to fix the service=driveway Wiki page which we have already accepted will be left in the US definition. Indirectly, this becomes a form of personal attack which is uncalled for.