Talk:Proposed features/kerb

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Not only the already noted completely level case, but we have lot's of places where the curb at a crossing is part level, part lowered; cyclists get a smooth transition and pedestrians have the few cm high step. It's both and neither? Alv 07:48, 13 December 2010 (UTC)

Is the pedestrian side still lower than usual? Do you have any photos?--Pobice 09:57, 13 December 2010 (UTC)
(Seems I could have written with a more specific description.) Yes, all of the crossing is (most of the time anyway) lowered, the stone has just been replaced with a stepless and very shallow asphalt slope on the cycling part. I might find a photo in my archives, but otherwise I'll need to wait for the snow to melt. Alv 17:45, 13 December 2010 (UTC)
So here's one:
. In this case the central island has a boundary stone on the cyclist part, too, but it's virtually flush with the surroundings, whereas the pedestrian side has a lowered curb. On the far side the flush cyclist part has no curb stone at all. Alv 12:26, 16 May 2011 (BST)
I think in these cases it might be best to map as two crossings then, unless you have any other ideas --Pobice 20:59, 16 May 2011 (BST)
As much as a segregated=yes foot&cycle way is best mapped as two parallel ways :) Alv 22:30, 16 May 2011 (BST)
I'd imagine in these cases you could either mark it as a double crossing, or map as an area --Pobice 18:41, 23 January 2011 (UTC)


Stale: Joshdoe 14:14, 28 July 2011 (BST)

Some sloped curbstones are combined with other measures to extend the slope onto the sidewalk; effectively equal to a lowered curb - but sometimes it's just a steep slope that one can cycle over slowly, but might pose a problem for wheelchair users. Would need some thought or reasoning which is it. Alv 07:48, 13 December 2010 (UTC)

Could possibly mark with wheelchair=no in such a case --Pobice 09:56, 13 December 2010 (UTC)
There's more to it, sadly: sometimes it's even on a raised kerb (hard to cycle over at all without "jumping" the front wheel), sometimes it's just low enough for a wheelchair but steep enough to be at even more annoying for a cyclist than your average lowered kerb. Alv 18:00, 13 December 2010 (UTC)
Sounds like you may need to have a go at your local highways department :D. I'm having trouble visualising this as I would have thought anything that proved troublesome for a bike would cause as much a problem as for wheelchair users --Pobice 23:06, 13 December 2010 (UTC)
At 10+ km/h (or even 30+) the abrupt upward motion (of more than a few cm) shakes the handle bar (and the whole bike) violently, if not dangerously, yet it can be within the 6 cm maximum for "wheelchair approved". Any "normal" lowered kerb is usually, what, 2 to 3 cm? It probably looks exactly like the one described below, albeit it's a bit lower than that. Alv 16:22, 20 December 2010 (UTC)
6cm is not "wheelchair approved". German standard for wheelchair approved is 3cm. 6cm is a bad compromise (I guess from wheelmap?), so that there are accessible doorsteps at all ;-) Source of 3cm: Richtlinie zur Anlage von Stadtstraßen von 2006 (RASt) --Lulu-Ann 16:28, 21 December 2010 (UTC)
I've been using sloped_curb=yes in my neighborhood; would this proposed tag replace that one? The photo in that article is exactly what I'm talking about. - Joshdoe 20:14, 18 January 2011 (UTC)
Hopefully yes its would--Pobice 09:01, 21 January 2011 (UTC)

Keep the usecase in mind

Stale: Joshdoe 14:14, 28 July 2011 (BST)

What is the usecase for this proposal? I see these usecases:

1) A person on wheels (large electic wheelchair, agile small wheelchair, rollator, bicycle, inline skates, stroller) wants to find a route that can be managed.)

2) A person on wheels wants to find a raised kerb at a bus stop so entering / leaving becomes easier.

3) A blind person wants to find a route where it is sure that the kerb can be identified easily, so he/she does not run on the car lanes accidently.

A minimum of 3cm is a common compromise in German street building engineering to encounter the needs of 3).

But persons with different wheeled vehicles have very different needs how high a kerb can be to be passable.

Also an orinary kerb in the USA has the hight of a raised kerb in Germany.

Conclusion: Map kerb hights in centimeters, so each user can configure the routing engine to find an individual route with maximum passable kerb hights.

Example: kerb_hight=5 --Lulu-Ann (talk) 11:12, 2 October 2013 (UTC)--Lulu-Ann 12:04, 13 December 2010 (UTC)

Its more for wheelchair users, but also considering the other two cases. Its also an attempt to marry existing proposals with some of the ahoc tags currently in use. The idea first cropped on with regards to bus stops and not been able to use wheelchair=yes or limited without knowing the types of bus serving at a stop.
I'm not sure I like mapping the heights - it leads to a false sense of accuracy unless you measure one. Also I'm not sure the US mappers will be happy mapping in meters. I'll happily add it as an option and possibly add a size range to the text options.--Pobice 23:28, 13 December 2010 (UTC)
Not mapping the hights but a vague estimation of what persons consider "normal" or "raised" gives a *guaranteed* unaccuracy.
"A good estimation is better than a broken ruler" my mom uses to say :-)
The world does not have sympathy for persons using imperial units. Not in this and not in other OSM proposals... You can add a conversion feature to editors. Nobody did this up to now, so there is obviously no need... btw, dividing by 2.5 is multiplying by 4 and moving the decimal point one digit to the left. The inaccuracy caused by this rough conversion is smaller than the one caused by a pebble in the gutter. --Lulu-Ann 16:02, 14 December 2010 (UTC)
Actually yes they do! Other tags allow imperial values. --Pobice 17:04, 14 December 2010 (UTC)
No, they don't. "Imperial mappers" keep adding such comments ;-) --Lulu-Ann 14:47, 15 December 2010 (UTC)
It is easier to add unit conversion to 3 or 4 editors than to 1000 navigation softwares. --Lulu-Ann (talk) 11:12, 2 October 2013 (UTC)
I would prefer it, if the actual height was in a different key (e.g. kerb:height=0.15). If you use kerb=0.15, you also need to know how low the floor of the bus/tram/... is, to know if the entrance is stepless. With kerb=raised you can assume, that it will be stepless and ommit calculation. --t-i 16:42, 3 January 2011 (UTC)
Getting into a vehicle is not the only usecase of kerb hight. Raised kerbs at bus stops only lower the step, they do not guarantee stepfree entry. Also different bus services will have different entry hights. We need to calculate anyways. --Lulu-Ann 17:04, 3 January 2011 (UTC)
This is the reason why it was suggested not to use wheelchair=yes unless you knew all buses serving the stop are of the right type. --Pobice 18:43, 23 January 2011 (UTC)

Kerbs at bus stops

Resolved: Joshdoe 14:14, 28 July 2011 (BST)

How do you want to map kerbs, when there is a raised and a lowered kerb at a bus stop? --Lulu-Ann 12:11, 13 December 2010 (UTC)

  • Leave the kerb tag off
  • Map each platform with kerb=raised or not
Leaving the kerb tab off does not make sense. There is only one platform, with a lowered kerb for 1.5m and the rest is raised (where the bus stops). --Lulu-Ann 14:45, 15 December 2010 (UTC)
It all depends on how the bus stop is mapped. If it is mapped as per documentation (ie one node bysides way) then add kerb=raised to that node. Otherwise add public_transport=stop_position with kerb=raised --Pobice 19:12, 15 December 2010 (UTC)

Kerbs at crossings

How do you want to map kerbs, when there is a crossing of two streets and there are footways on both sides of each street, with different raised or normal kerbs at the pedestrian crossings? --Lulu-Ann 12:11, 13 December 2010 (UTC)

Map one crossing as kerb=lowered and one as kerb=yes--Pobice 17:14, 14 December 2010 (UTC)
Not senseful for routing for the blind. --Lulu-Ann 14:45, 15 December 2010 (UTC)
Not sure what you mean here? --Pobice 18:46, 23 January 2011 (UTC)
There's no easy solution if you use kerb=* on the crossing node, it's better to put two nodes on the footway at the locations of the actual kerbs. Then you can map a dropped/lowered/ramped curb on one side, and a normal curb on the other. And don't put kerb=* on the highway=crossing node. -- Joshdoe 14:14, 28 July 2011 (BST)

Kerbs at traffic islands

Stale: Joshdoe 14:14, 28 July 2011 (BST)

How do you want to map kerbs at traffic islands? --Lulu-Ann 12:11, 13 December 2010 (UTC)

Node: kerb=lowered if lowered at both sites + either missing or lowered on traffic island
Area: kerb=yes on area if island has a kerb. Add kerb=<kerb status> to the nodes where the footway crosses the kerb area boundary--Pobice 17:16, 14 December 2010 (UTC)

Kerbs at footways

Stale: Joshdoe 14:14, 28 July 2011 (BST)

How do you want to map kerbs, when there are single ways for footways and bikelanes at a crossing? --Lulu-Ann 12:11, 13 December 2010 (UTC)

You mean one where the kerb has is lowered for half and not for the other?--Pobice 17:19, 14 December 2010 (UTC)
Probably going to have to micromap in these cases, or possibly map as two crossing. --Pobice 18:48, 23 January 2011 (UTC)

Another type of kerb

Resolved: Added value of "rolled". --Joshdoe 14:14, 28 July 2011 (BST)

Here is another cool type of kerb (I will add photos as soon as the snow has gone): The kerb is at normal hight, but there is a micro ramp: The kerb is cut off so there is a 45° angle.

This is nice for cars, because they can get up the kerb easily, and it is nice for bycicles on the cycleway on the upper side of the kerb, because the cycleway does not go up and down like it used to be built here when the kerb was lowered in earlyer times. It is not nice for wheelchair drivers, as it is not very suited to be climed with a wheelchair.

How would we call this?

--Lulu-Ann 12:48, 20 December 2010 (UTC)

kerb=slopped is tempting but might confused. kerb=angled? --Pobice 18:50, 23 January 2011 (UTC)
There are many of these types of curbs in my area, Fairfax County, Virginia. It appears that in the US these are called mountable curbs, as opposed to barrier curbs. Also check the Wikipedia article for other terms. Unless a UK term is offered, I propose that for these kerbs we use kerb=mountable, and that it implies accessibility by vehicles, including bikes, and wheelchair=no unless tagged otherwise. -- Joshdoe 14:04, 29 March 2011 (BST)
Perhaps kerb=rolled would be more appropriate given this? -- Joshdoe 14:12, 29 March 2011 (BST)
I think kerb=rolled is possibly the better term for this as it describes the kerb a little better. Plus many drivers still manage to mount 'non' mountable kerbs :)--Pobice 20:25, 29 March 2011 (BST)

Kerb direction

Stale: Joshdoe 14:14, 28 July 2011 (BST)

Should we adopt a "footpath at left-hand side of way" convention, like we have for water, cliffs, etc ? I think it would avoid confusion, notably when there is a footpath "island" between lanes of traffic. --Vincent De Phily 12:17, 29 June 2011 (BST)

I'm not entirely sure what you mean; do you have a photo or good aerial image to demonstrate this? I'm guessing you're talking about ways tagged with kerb=*, something that I don't think is mentioned in the proposal. My thoughts are that this tag will primarily be used on nodes of crossing ways, such as at the actual location of the kerb, or alternatively at the crossing node itself, but not on ways themselves. If you could expand on your intentions for this tag that would be helpful. -- Joshdoe 12:11, 30 June 2011 (BST)


Would height=* attribute be useful? It's not hard to measure it. --Zverik 15:06, 26 July 2011 (BST)

kerb:height is in the proposal, although doesn't feature prominently as its much quicker to note the kerb type than it is to go round actually measuring it. --Pobice 02:04, 27 July 2011 (BST)
Oh. I suggest making default units mm instead of m. Also, when does the voting start? --Zverik 06:30, 27 July 2011 (BST)
That the default would be mm (why not cm, for example?) is not at all obvious without looking it up. And if you need to consult the wiki for a default, that default should not be relied on anyway. For tags where the usual default of meters doesn't fit the scale well, this just means that you should always include the unit. --Tordanik 11:11, 27 July 2011 (BST)
We have already kph for speed, m for regular heights, mm for railway gauges etc. There are always defaults best suited for the tag. If it's just height=*, then m is assumed, but for kerb:height=* mm can be used. --Zverik 11:20, 27 July 2011 (BST)
Speed always uses kph as the default, whether you're using maxspeed=* or minspeed=*. Railroad gauges are a bit different. Although most gauges, including the Standard Gauge (the most common by far), were originally defined using inches and feet, it is common practice, at least in an international context, to use millimeters. OSM tagging therefore adopted this convention. However for kerb heights, I must say I tend to like using mm over m, considering that it is likely there are no kerbs over a meter in height. It would be nice if we can point to an international convention or standard which uses mm for kerb heightths. -- Joshdoe 15:28, 27 July 2011 (BST)
Defaults should (imo) only be used in OSM when it's obvious for those mappers who are likely to use a tag what the default would be. Railway gauges may be such a case, but kerb heights are certainly not. Therefore, the best course of action would be to not define a default at all, and instead make it clear that explicit units should always be used for kerb:height=*. --Tordanik 16:23, 27 July 2011 (BST)

Kerb on ways

I think we need to reintroduce the use of kerb tab's on ways. I can see it been used as such on platforms mapped as areas and the odd unusual street. For example in my home town around the market the kerb's are all flush with the road on one side of the street, but some times not the other. It could also be used if we start maping traffic island as areas.--Pobice 01:20, 28 July 2011 (BST)

I don't think I see anything wrong with allowing this tag on ways, although perhaps it should be stated that when footways/paths/cycleways intersect with the kerb, the intersection node should also be tagged with kerb=*, as I don't think we want to require data consumers to do the additional processing that would be required otherwise to determine the presence of a kerb. -- Joshdoe 11:19, 28 July 2011 (BST)
Sounds sensible to me --Pobice 11:40, 29 July 2011 (BST)

Changing the value "lowered"

It seems we've nearly invented the term lowered that doesn't have any significant usage in the real world. Not that Google search results are the be-all and end-all, but search results for the terms are as follows, accounting for both the curb and kerb spelling (though in this list I only use kerb):

  • "kerb cut" (443,000)
  • "kerb ramp" (305,000)
  • "dropped kerb" (241,000)
  • "lowered kerb" (11,300)
  • "pram ramp" (4,550)

I would say cut is not very descriptive, so I propose we eliminate the value lowered, and replace it with either dropped or ramp. Personally my vote is for ramp, as I believe this is most descriptive. Also, dropped to my mind sounds too similar to flush. Some might complain that ramp is a noun and all the other values are adjectives, so perhaps we could use ramped, though that sounds even more awkward to my ears. -- Joshdoe 11:43, 28 July 2011 (BST)

There may be many uses of "kerb ramp", but a google image search shows a lot of things that I would not consider a "lowered/dropped kerb" (it mostly shows plastic ramps). The term "dropped kerb" might be appropriate - but I have no idea what a native speaker might associate with this term. --Tordanik 12:49, 28 July 2011 (BST)
+1 for "dropped". A ramp could either be a lower or higher than normal kerb, where as dropped makes it clear its a lower than normal kerb. There are 500 odd instances of lowered (a large number of which are mine) but I'm happy to switch--Pobice 11:45, 29 July 2011 (BST)
+1 for "Dropped"; the correct British English. Andy Mabbett (User:Pigsonthewing); Andy's talk; Andy's edits 10:04, 24 March 2015 (UTC)

Values "normal" and "raised"

Some on the mailing list mentioned that they'd like to see the value normal return, however I don't think we can do that without changing the raised value. It must be understood that normal means something different to someone from the US and the UK (not to mention the other English speaking countries). As I described on the mailing list, the most common (i.e. normal) kerb height you'll encounter in the US is 6 to 8 in (15 to 20cm), while in the UK it is apparently much shorter. A "normal" kerb in the US is closer in height to a "raised" kerb in the UK, and thus the confusion. Here are the possible values I suggested on the mailing list:

  • normal: most common kerb, unsuitable for wheelchairs, difficult for the bicycle/mobility impaired, anything above 3cm (height varies by country)
  • bus: specifically at a height intended for use with buses (whatever height is appropriate in a given country)

Those in the US would change all the tags for existing objects from raised to normal, while those in the UK would change raised to bus. Feel free to suggest better alternatives. -- Joshdoe 12:13, 28 July 2011 (BST)

We need values for "normal" and "higher than normal", with the latter usually intended for entering public transport vehicles. Calling these "normal" and "bus" seems acceptable, unless someone can suggest better values. Avoiding "raised" entirely is probably best, because native speakers have that annoying tendency to treat OSM tags as if they were normal words and ignore the definitions. ;) --Tordanik 12:45, 28 July 2011 (BST)
We do not need values, because each wheelchair driver has a certain hight he or she can manage, and a reasonable estimation in cm is better than a rounded value to some invented standards. Use "estimated_hight" instead. You can not expect travellers to another country to learn the values for your invended standards. And you can not expect any router to learn different standards for each region (Ja, Bordsteinkanten werden von Tiefbauämtern gemacht, und die sind kommunal!!!) There is a standard, and it is called centimeter. Use it. It will work for sure. --Lulu-Ann 15:18, 17 February 2012 (UTC)

Armchair mapping and kerb features

Should kerb=yes be applied during armchair mapping to indicate the visual boundary between roadway and footway? --Ceyockey 23:36, 11 February 2012 (UTC)

I've been doing this, but have been using kerb=unknown instead, since with armchair mapping you can't be sure there's a kerb at all. In other words I'm using the tag to indicate I strongly believe there is some type of kerb there, but I can't be sure what type it is or if it even exists. -- Joshdoe 01:29, 12 February 2012 (UTC)
Do not use "unknown". Use "FIXME=Kerb" instead. Everybody is looking for fixmes in quality assurance, noboby is looking for "unknown". --Lulu-Ann 15:14, 17 February 2012 (UTC)
OK. I've changed most of what I had introduced as kerb=unkknown to FIXME=kerb; revisions found in changeset 10736259 (64 nodes). There are likely some others about, but this is the bulk of the additions I've made. Looking at TagInfo, though, there are >850 instances of kerb=unknown about. --Ceyockey 00:07, 20 February 2012 (UTC)

Backwards compatibility with sloped_curb

This proposal supposedly replaced the use of sloped_curb or maybe it didn't. In any case for it to be backwards compatible it however should likely allow side suffixes on the key when used on a crossing node:

kerb:left= ... kerb:right= ...

SimonPoole (talk) 11:50, 3 March 2016 (UTC)

Use as refinement of barrier=kerb

It would seem that kerb=... could potentially be used as additional refinement for barrier=kerb, this should be detailed. Note it is unclear if kerb:left/right would make any sense in such a context.

SimonPoole (talk) 11:50, 3 March 2016 (UTC)