Talk:Key:maxweight

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Max Weight for "Combinations"

Here in the US, we sometimes have some bridges that have weight limits for trucks that have a single trailer, or for ones that have two. One bridge near where I live has the following sign for it (I'll post the picture later, but here's the text of it): BRIDGE | WEIGHT LIMIT 16 TONS | EXCEPT COMBINATIONS 26 TONS How can we go around to tag for this? --Rickmastfan67 05:02, 18 August 2010 (BST)

MaxWeightOneWehicle.png
In czech, we have sign for maxweight + table for "one wehicle" - ie: 25tons / 50tons one wehicle --Jezevec 22:18, 5 October 2012 (BST)
Yes, and sometimes there is also no weight listed for the combinations (which I presume may mean that they are forbidden?). For example, this bridge was recently posted as 29 tons max except combinations. --Abbafei (talk) 04:24, 18 November 2014 (UTC)

Gross vehicle weight rating (GVWR)

Background / Research

There is a difference between the "actual weight" of a vehicle (as measured by a weighbridge) and its "gross vehicle weight rating" GVWR. The GVWR, or sometimes simply "Gross Vehicle Weight" is a maximum operating weight as specified by the manufacturer and recognised by the local state/government. For hgv routing, it is necessary to differentiate between those two. -- Eckhart 10:57, 22 November 2012 (UTC)

Agree, we need this, because the the Vienna Convention on road signs defines both. The GVWR is called "permissible maximum mass" in the convention and is defined as "the maximum mass of the laden vehicle declared permissible by the competent authority of the State in which the vehicle is registered" [Article I, (r)]. The actual weight is called "laden mass" in the convention [Article I, (s)] and is defined as "actual mass of the vehicle as loaded, with the crew and passengers on board".
If the convention has been accurately ratified by the state/government, then any weight value used in connection with a "no entry for goods vehicles", "prohibition of overtaking" and "speed limit" sign - no matter if inscribed or on an additional panel - means "permissible maximum weight" (i.e. GVWR). Thus:
  • UK traffic sign 622.1A.svg, Vorschriftszeichen 7a Gewicht.svg or this German example means "No entry for goods vehicles with gross vehicle weight rating GVWR > X".
  • Speed limit of 60 for HGV with weight more than 7.5t.jpg also applies to HGVs with a gross vehicle weight rating GVWR > 7.5t only.
For countries who accurately ratified the convention a standard weight restriction sign (such as Vorschriftszeichen 9c.svg or this German example) refers to the "laden mass" (i.e. actual weight). I think there is an agreement that roads with such signs should be tagged with maxweight=*. As correctly pointed out by Eckhart, gross vehicle weight is not needed for this type of sign.
As this convention is implemented by many countries in the world we require a gross weight property in order to tag the road signs correctly.--Martinq 14:38, 22 November 2012 (UTC) and edited by RobJN 20:06, 27 November 2012 (UTC)


Austria I don't know if the Austrian law (StVO) defines a weight value under a speed limit sign as gross weight or just as weight. According to the convention it should be Gross Vehicle Weight Rating (GVWR), but the Austrian StVO neither clearly says 'weight' nor 'gross weight'.--Martinq 21:51, 22 November 2012 (UTC)

United Kingdom In the United Kingdom (and likely due to legacy non-metric signs) the Vienna Convention has not been ratified/implemented. All weight signs refer to the Gross Vehicle Weight Rating. For more see link.

Finland

  • laden weight: Finland road sign 344.svg and Finland road sign 345.svg and Finland road sign 346.svg and Finland road sign 347.svg
  • GVWR: Finland road sign 313.svg with an additional panel stating the mass (that is, like in that German example above). (Prohibiton of overtaking and maxspeed signs may not have additional panels here.) Alv 22:20, 27 November 2012 (UTC)

Possible Solutions / Tags

I propose to add the vehicle property "grossweight". Example usage: hgv:conditional=no @ (grossweight>7.5) -- Eckhart 10:57, 22 November 2012 (UTC)

I would suggest using a new restriction tag (rather than a conditional property), for example hgv:max_gvwr=7.5. Alternatively the type of weight could be specified independently of maxweight=*. One possible way to do this is to tag maxweight:type=GVWR. --RobJN 20:06, 27 November 2012 (UTC)

Support for "no weight limit"

Some cases have no sign posted - what may be used to tag this? unsigned, none are rare but present. I prefer unsigned as there are sometimes some default limits (law typically limits dimensions and weight of vehicles, there are obviously also physical limits).

So, I propose to mention "unsigned" at wiki page Mateusz Konieczny (talk) 14:03, 30 June 2017 (UTC)

  • It would be useful both to detect unsurveyed location and for routing to avoid routing over places where it is unknown whatever weight limit exists Mateusz Konieczny (talk) 18:34, 30 June 2017 (UTC)
The vast majority of roads have no explicit weight limit posted, though, so this is clearly the default situation. When there's such a clear default, it's not common to explicitly tag the absence of a special case, even if such a value exists. (We don't tag oneway=no + bridge=no + tunnel=no + covered=no + access=yes on normal roads, for example). Now I'm aware that there are arguments in favour of doing exactly that, but it would at least be a significant change in existing tagging philosophies. --Tordanik 22:06, 1 July 2017 (UTC)
I thought about doing it for bridges, obviously doing it for every single road would be ridiculous. Mateusz Konieczny (talk) 08:00, 3 July 2017 (UTC)
How about maxweight:signed=no? I think this scheme is used in a couple of other places as well already. --Westnordost (talk) 21:00, 26 January 2019 (UTC)

Units

The page Units list the default units. There is no required unit forthis or any other dimension, use the unit of the feature and add the unit after the number separated by a space. Please use units that are identifiable and in common use. If the page Units does not list the units you are using consider adding it there. Warin61 (talk) 23:02, 26 January 2019 (UTC)

Abbreviation for U.S. short ton

@Westnordost Thanks for noting the distinction between short and long tons. Your example uses "st" as an abbreviation for "short ton"; however, "st" can also be an abbreviation for the stone, another unit of weight. Are we sure that there are no legitimate uses of stones in other tags that could cause confusion with this usage? (I don't know, maybe something related to horse racing facilities?) Most U.S. mappers have avoided this issue entirely by converting to (international) pounds with the suffix "lb" or "lbs". – Minh Nguyễn 💬 06:11, 18 April 2019 (UTC)

The "st" in OSM context has always been defined as "short tonnes", see https://wiki.openstreetmap.org/wiki/Map_Features/Units#Explicit_specifications . If something really is specified in stones in reality, another abbreviation/unit must be used. I.e. "stones" - it's not that long ^^ --Westnordost (talk) 09:15, 18 April 2019 (UTC)
@Westnordost Looks like the st suffix was added to the page a year ago by Maxerickson and was used for the first time in OSM on May 24. [1] Mappers have been entering short tons as pounds since at least 2009, and in much greater numbers. Has this change to the wiki been discussed anywhere else? Do we know if any data consumers know how to handle st, or do we need to raise awareness of the suffix? I could imagine a scenario where truck routers have been parsing lb and lbs all these years, based on existing usage, but their developers would be caught by surprise as that suffix gets replaced by st on some important road. – Minh Nguyễn 💬 23:04, 24 April 2019 (UTC)
Yes, I added it out of frustration with the circular logic that people were using to argue against adding values that appear directly on signs. It wasn't documented in the wiki, so people said it wasn't okay to use it. I'm pretty sure that people accidentally tried to use it (or just put t) lots before I added it and then had their edits fiddled into the lbs. Maxerickson (talk) 21:22, 26 April 2019 (UTC)
@Maxerickson Fair enough; that's also my understanding of what has happened in the past. Have there been any mailing list discussions and bug reports for editors and routers that you know of? I like the st suffix in principle, but it feels like more needs to be done in order to make the suffix a reality. – Minh Nguyễn 💬 01:11, 27 April 2019 (UTC)

Restrictions for different classes of HGV

@Minh Nguyễn Regarding the example you added for this sign, the current tagging written there is wrong, probably a copy&paste error.
MUTCD R12-5.svg

But the question is, how to map this at all? There is hgv_articulated=* for the second row, but no hgv_trailer=* or similar for the third (yet). But since having a trailer is a property any vehicle may temporarily have, it is maybe not appropriate to define hgv_trailer, bus_trailer, car_trailer etc. etc. but solve this instead with conditionals. Does this make sense?:
maxweight:hgv=8 st
maxweight:hgv_articulated=12 st
maxweight:hgv:conditional=16 st @ (trailer)

—Preceding unsigned comment added by Westnordost (talkcontribs) 09:28, 18 April 2019‎ (UTC)

@Westnordost Yeah, I didn't realize the sign was distinguishing between box trucks and trailer tractors, so I used maxaxleload=* as a shortcut; my mistake. I'll admit that I generally find MUTCD weight limit signs almost as confounding as MUTCD hazmat signs, so I'm glad you're double-checking my changes. (For reference, this particular sign is described in the national standard.) I think your suggestion makes sense, though I wonder if maxweight:hgv=* should be tagged at all or whether both conditions should be listed in maxweight:hgv:conditional=*.

For what it's worth, I just picked an image that was already available on Commons, but the weight limit signs can get more complex. For example, the "Single Unit Vehicles" sign in this photo is meant for garbage trucks, water tankers, and the like. I'm not sure if I got the tagging right in way 153028430.

 – Minh Nguyễn 💬 23:18, 24 April 2019 (UTC)

That looks about right. Man, these signs are so small, you need binoculars to read them as a truck driver! :-o
Would have been easier for the road traffic authority to post a maxaxlewheight sign with roughly the same outcome --Westnordost (talk)
I'd imagine the primary purpose of a sign like that would be to give the police a better legal argument if a truck driver challenges a citation. But truck drivers often have other ways to be informed of the most important restrictions, whether it's a weigh station (as in this case), statewide hotlines, automated broadcasts over localized CB radio (which would be an interesting feature to map for sure), or routing applications. – Minh Nguyễn 💬 23:53, 25 April 2019 (UTC)