The Maarssen Mapper has commented on the following diary entries

Post When Comment
Tool for measuring elevation above sea level on the OSM map 6 months ago

@Alex-7 My point is simply that an elevation as a number, with no frame of reference, is useless. Just like an amount of money with no currency, or a lat/lon with no CRS. It is not about the accuracy of the measurement, or the quality of the value as such, but it can only be used if it is placed in the right context. Local datums do not join up seamlessly, and global datums are not widely used by "normal people" like mappers. We have a challenge to square that circle.

Tool for measuring elevation above sea level on the OSM map 6 months ago

How do we denote the datum used in an ele=* tag? There are thousands of different versions, depending on where you are. Some transformations are also dynamic, i.e. they may change over time. The wiki page for ele=* says to use Mean Sea Level on the the EGRM96 geoid, but I doubt many "normal" people will be aware of what that entails and how that relates to any local reference datum. If the elevations are not associated correctly with a datum, errors will occur... There is a difference of over 2 metres between the local datums of Belgium and the Netherlands for example.

For global maritime use MSL is often used, whereas on land the local datum is often more prevalent. In ports etc. LAT (Lowest Astronomical Tide) is also used.

Vertical datums are just as big an issue as the 2D coordinate systems - possibly a bigger problem because of the lack of awareness.

A Suggestion to Fix Poor LSN in the UK almost 2 years ago

Alex, you don't do yourself any favours with these baseless comments. I have not removed any files, nor "restored any access" nor taken any other action which may explain your observation, which by the way you have still not explained. Your conspiracy theories are incredible. I would like to remind you that you brought this current animosity on yourself by stomping on the work of others without taking the trouble to investigate the background - and then you have the gall to accuse me of that same offence when I correct the situation. Whether you trust my statements or not is of course up to you, but I make them in good faith. Your accusations are bordering on slanderous. I don't really care about your private beliefs. Please keep your ad-hom comments to yourself. If you can't behave like a decent OSM citizen, you might consider whether it's an appropriate environment for you.

A Suggestion to Fix Poor LSN in the UK almost 2 years ago

What I meant by OS not being the owner of this information, is that they do not define the boundaries, nor the names of parishes etc. They are formally informed of any changes through changes in secondary legislation and formal notifications from competent bodies.

Re: "unnamed parishes" - I was responding to your reply to TomH about Unparished Areas, where you suggest that OS defines these boundaries, that they are verifiable (how?), that they are named by their District councils, and that one may/would refer to them as an "Unnamed parish":

"oddly, these are all as carefully defined by the Ordnance Survey as are the civil parishes, and therefore are all perfectly verifiable. They are also all named by their respective District councils, and by those that live within them (I mean, can you imagine: “Where do you live?” “Oh, I live in Unnamed parish 9346”)."

The Localism Act 2011 only confers meta-powers to parishes in that a parish council does not automatically get these rights; it first has to demonstrate/resolve that it is "eligible" and must remain so. It can only use these powers to do things that "anyone" can do, so it can't do many things that are reserved to higher powers. It seems these powers have proven very useful in certain specific cases, but I am not sure if there is a general power transfer going on. To start with, parishes only have one source of tax income (the precept) and are answerable to the electorate for that.

I haven't removed any files or links as far as I know... If you can give a specific example I will look into it!

A Suggestion to Fix Poor LSN in the UK almost 2 years ago

Alex, the OS is not the owner of these boundaries - they are just the messenger. In their data they do not refer to "unnamed parishes" - there is no such thing. The polygons we are talking about here are "filler areas," which do not have an official name (and indeed no name is supplied by OS).

It appears that your most fundamental worry is that LSN is not working (properly). I am not 100% sure but I believe that Nominatim is not officially a core part of OSM, in the same way that Mapnik (which renders the map tiles) and its governing style sheets are not. Maybe they can be considered examples of good practice, or possibly even reference implementations. The normal attitude if you consider it broken is to (offer, help to) fix it. I agree with you that there is room for improvement here, but the Right Way (and in this case probably the Hard Way) to address it is to improve Nominatim, not to work around these shortcomings by manipulating the underlying data to produce the results you expect.

A Suggestion to Fix Poor LSN in the UK almost 2 years ago

This statement is untrue: Powers: In theory Parish & Town Council powers are identical to those of a District. However, they mostly do not have the resources to do anything more than Leisure Services.

Parish and Town councils have very limited powers and are in no way equivalent to a District. This also applies to large town/city councils such as Salisbury - which is simply a Parish Council with a fancy name.

A Civil Parish council can pretty much unilaterally choose to style itself as a Town, Village, Community or Neighbourhood Council. The differences are only symbolic, there is no change to the powers of the authority. City status can only be bestowed by the Crown however, you cannot just call yourself a City. Similarly with Borough status - this is simply a binary flag which a given LA either has, or has not. Neither City nor Borough status changes the fundamental powers of the council.

You didn't speak to the Boundary Commission by the way, but to the Local Government Boundary Commission for England. The Boundary Commission deals with parliamentary constituencies and their constituent wards, and the LGBCE deals with local government district boundaries and electoral wards. Parish boundaries and their warding arrangements, together with their electoral situation (parish meeting or parish council, grouping etc) are however an internal affair for the parent District/Unitary concerned.

Parishes, and Unparished Areas, are of little use for many use cases as they are not involved in postal addressing and are frequently divergent from local perception. However there are occasions when you need to know the responsible authority for a given location, including not only local government but also things like emergency services and health care provision.

Nottinghamshire Civil Parishes - names for unnamed areas almost 2 years ago

Alex, please go easy on the personal affronts. I have considerable knowledge and experience of UK local government and administrative boundaries. Where you think I am based is of no relevance to the facts. If your understanding of the subject was better you would realise why things are like they are, and why it's best to ask before unilaterally upending the status quo.

--The Maarssen Mapper

Repairs to Woodsetts CP Boundary almost 2 years ago

The issue with the quotes is fixed now. --colin (csmale)

Repairs to Woodsetts CP Boundary almost 2 years ago

Thanks for pointing out the issue with the quotes in the URLs. I will fix this ASAP. --colin (csmale)

Complex Intersections, or Why We Should Get Rid Of exit_to almost 4 years ago

I don't think there's any reason to limit the use of destination=* to *_link ways. It's useful for all kinds of junction topologies, not just simple motorway exits. There is a difference between routing (a mathematical exercise) and navigation - which means giving useful, relevant instructions to a human. Normal practice here (NL) is that destination and destination:ref reflect the signage (irrespective of what "seems logical"). In some places the junction number is prominent and important for navigation (e.g. the UK - you might say "turn off at junction 24") and in other places the junction number may not be so relevant. By keeping the tagging distinct you allow the navigator the freedom to present the information in different ways.