Re: [Talk-us] Maxweight in the USA
On Thu, Nov 5, 2015 at 2:10 AM, Bryce Nesbitt wrote: > All that faded, including the signs, and its really clear in the USA it's > feet for elevation and mph for speed limits. Well, on DOT signage, only if the numerals are not circled. http://www.us-metric.org/mutcd-and-metric-road-signs-in-the-us/ ___ Talk-us mailing list Talk-us@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-us
Re: [Talk-us] Maxweight in the USA
On Mon, Nov 2, 2015 at 4:50 PM, Mike Thompson wrote: > The number of places to the right of the decimal separator has meaning, it > indicates the precision of the value. Thus > 80,000 lbs <> 36.28739 metric tons, even though that is what the > mathematical conversion produces. To say that the two are equal implies > that the state has equipment (weigh bridges / truck scales) which can > detect changes of as little as 0.02 pounds in a fully loaded semitrailer > truck and that they actually care about such small variations (a change in > the fifth digit to the right of the decimal of a metric ton value = 0.2 > pounts). One of the great things about OSM is that it does support multiple > units. Writing a parser to read the value of an OSM tag and convert to a > common unit is easy to do for the data consumer (having just done it with > the height tag). > Just as we shouldn't tag for the renderer, we also shouldn't devise humanly hositle tagging schemes, like forcing unit conversions on regions that use a different system of measure. That's a political problem affected areas should work out with their governments, and we're just going to have to deal with the fact we're working with multiple sets of units until the last three holdouts get on board. ___ Talk-us mailing list Talk-us@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-us
Re: [Talk-us] Maxweight in the USA
On Mon, Nov 2, 2015 at 4:28 PM, Toby Murray wrote: > My view is that this isn't much different than speed limits. We don't > tag maxspeed=96.5606, we tag maxspeed=60 mph. Tag what's on the sign. > The complicating factor on this is of course that "ton" has at least 3 > different meanings but I would generally assume that weight > restrictions in the U.S. are tagged in short tons because that's what > is on the sign. > I may convert this to pounds to avoid ambiguation, since folks often seem to get the distinction between t/tonnes and tons mixed up (the former is SI for 1,000kg, the latter is for 2,000lbs) ___ Talk-us mailing list Talk-us@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-us
Re: [Talk-us] Maxweight in the USA
On Mon, Nov 2, 2015 at 4:12 PM, Steve Friedl wrote: > This issue has come up as well with the height of mountain peaks; those of > us who hike in the mountains in the US know peak heights *only* in feet, > but OSM seems to reflect this in meters; this is entirely unhelpful to > local hikers. Us locals think of Sierra Peak as 4050 feet, not 928 meters. This has to do with the USGS GNIS data, which records these heights officially in meters. ___ Talk-us mailing list Talk-us@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-us
Re: [Talk-us] Maxweight in the USA
On Mon, Nov 2, 2015 at 3:59 PM, Andy Townsend wrote: > The relevant wiki page http://wiki.openstreetmap.org/wiki/Key:maxweight > does say "as of September 2014 only metric units of weight (metric tonnes > or kilograms) are supported for this tag". I'm unaware of any discussion > prior to the 17 September 2014 change (not that that means that it didn't > happen, just that I'm unaware of it). > I tag maxweights with units regularly, as despite the fact OklaDOT works in metric nearly exclusively internally, the nearest safe round number equivalent is used instead (ie, 100km/h becomes 60 MPH) for signage, and I'm going by the ground truth or public records (which use the third-world "pound/US ton/feet/miles/mph" system). ___ Talk-us mailing list Talk-us@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-us
Re: [Talk-us] Maxweight in the USA
I feel that all measurements recorded in OSM should include units. And that measurements should be in local units. A while back the Carter administration tried to force the metric system on the USA, which resulted in signs like: elevation 4000 feet 1219.20 meters Teaching people of course that the metric system is hard. Of course in a real metric environment you'd have signs at: 1000 meters 1500 meters 2000 meters or perhaps: 1000 feet 500 meters 2000 feet 1000 meters All that faded, including the signs, and its really clear in the USA it's feet for elevation and mph for speed limits. ___ Talk-us mailing list Talk-us@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-us
Re: [Talk-us] Maxweight in the USA
On 11/2/2015 2:28 PM, Toby Murray wrote: My view is that this isn't much different than speed limits. We don't tag maxspeed=96.5606, we tag maxspeed=60 mph. Tag what's on the sign. The complicating factor on this is of course that "ton" has at least 3 different meanings but I would generally assume that weight restrictions in the U.S. are tagged in short tons because that's what is on the sign. I would also agree with this, and I'm from a country that uses metric units. This is distinct from peaks, which have a height which does not depend on signage and is a measurement of the physical world. It's possible for two people to measure the same peak and get different measurements, but assuming decent signage* two people will get the same maxweight or maxspeed for the same road. The pendant with an engineering physics in me also desires to point out that neither metric tonnes or short tones are SI base units, and both are derived units. The SI base is kg, or you could measure in Mg. * Yes, signage is sometimes not decent. ___ Talk-us mailing list Talk-us@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-us
Re: [Talk-us] Maxweight in the USA
On Mon, Nov 2, 2015 at 3:12 PM, Steve Friedl wrote: > This issue has come up as well with the height of mountain peaks; those of > us who hike in the mountains in the US know peak heights *only* in feet, > but OSM seems to reflect this in meters; this is entirely unhelpful to > local hikers. Us locals think of Sierra Peak as 4050 feet, not 928 meters. > > The discussion was strictly informal, but I think a number of us liked the > idea to support a unit of measure, such as ele=4050ft or maxweight=10t > There are a couple of different issues with mountain elevations in the US. One - feet vs meters - Steve explained well. One other is the fact that many of the peak elevations in OSM in the US came from the GNIS import. The elevation values in the GNIS are not spot or surveyed elevations. The elevations in the GNIS are from the US National Elevation Dataset (NED). The NED is a gridded dataset and the elevation is only typically for that given grid cell, which may be as large as 30 x 30 meters. For example, Longs Peak in Colorado is officially 14,259 feet above sea level[1], but OSM shows it as 4340 meters [2], which is 14,239 feet. [1] http://www.ngs.noaa.gov/cgi-bin/ds_desig.prl [2] https://www.openstreetmap.org/search?query=longs%20peak#map=15/40.2544/-105.6136 > > ___ Talk-us mailing list Talk-us@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-us
Re: [Talk-us] Maxweight in the USA
On 11/2/15 4:59 PM, Andy Townsend wrote: > > I'm not from the US, and I'm not sure what the right answer is (if as > a community you're happy entering maxweight=4.5359237 it'd certainly > make everyone's lives easier), so I'm posting this here and then > retiring back across the Atlantic :) > i'm an advocate of tagging using local units. i have recently observed that a bunch of maxweight values i set to "10 tons" were changed to "10" with the default of tonne, which is of course not an equivalent unit. so i don't like the "si units only" clause, i don't like undiscussed tagging changes of this type, and i especially don't like bulk edits that introduce errors into the database. richard -- rwe...@averillpark.net Averill Park Networking - GIS & IT Consulting OpenStreetMap - PostgreSQL - Linux Java - Web Applications - Search signature.asc Description: OpenPGP digital signature ___ Talk-us mailing list Talk-us@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-us
Re: [Talk-us] Maxweight in the USA
The number of places to the right of the decimal separator has meaning, it indicates the precision of the value. Thus 80,000 lbs <> 36.28739 metric tons, even though that is what the mathematical conversion produces. To say that the two are equal implies that the state has equipment (weigh bridges / truck scales) which can detect changes of as little as 0.02 pounds in a fully loaded semitrailer truck and that they actually care about such small variations (a change in the fifth digit to the right of the decimal of a metric ton value = 0.2 pounts). One of the great things about OSM is that it does support multiple units. Writing a parser to read the value of an OSM tag and convert to a common unit is easy to do for the data consumer (having just done it with the height tag). ___ Talk-us mailing list Talk-us@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-us
Re: [Talk-us] Maxweight in the USA
On Mon, Nov 2, 2015 at 2:12 PM, Steve Friedl wrote: > This issue has come up as well with the height of mountain peaks; those of > us who hike in the mountains in the US know peak heights *only* in feet, > but OSM seems to reflect this in meters; this is entirely unhelpful to > local hikers. Us locals think of Sierra Peak as 4050 feet, not 928 meters. > > The discussion was strictly informal, but I think a number of us liked the > idea to support a unit of measure, such as ele=4050ft or maxweight=10t > I think it's time the US community considered running it's own tile server. Not only could elevation be given in feet, but we could add highway shields. This isn't a trivial task, but it makes sense to produce a map that is more appealing to US users. Since we are about the only country that hasn't seen the light and switched to metric, at least we could do is make a map in imperial units. Clifford -- @osm_seattle osm_seattle.snowandsnow.us OpenStreetMap: Maps with a human touch ___ Talk-us mailing list Talk-us@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-us
Re: [Talk-us] Maxweight in the USA
My view is that this isn't much different than speed limits. We don't tag maxspeed=96.5606, we tag maxspeed=60 mph. Tag what's on the sign. The complicating factor on this is of course that "ton" has at least 3 different meanings but I would generally assume that weight restrictions in the U.S. are tagged in short tons because that's what is on the sign. Toby On Mon, Nov 2, 2015 at 3:59 PM, Andy Townsend wrote: > Just a heads up... > > There's a bit of a discussion going on at the moment as to whether it makes > sense to store SI units (or actually a derivative - metric tons) in > maxweight tags. I noticed a few changes (initially to other values in the > UK), and commented on https://www.openstreetmap.org/changeset/35009662 , and > the person making a changes (who's the author of one of the popular routers > using OSM data) wrote a diary entry here: > https://www.openstreetmap.org/user/karussell/diary/36220 . > > The argument in favour of the change is that storing an SI derivative makes > the data easier to consume; my counter-arguments are that (a) it makes it > harder for mappers to verify values and (b) anything consuming data > shouldn't assume the data is valid anyway (for "Bobby Tables" reasons if for > no other). > > Whilst doing this I noticed that a bunch of other "x tons" weight limits had > had values changed a while back (see for example > http://www.openstreetmap.org/way/32719427/history ). That's now been > changed to "maxweight=4.5359237" which is at least not heavier than the > actual posted restriction. However there are still some other integer > values without units which implies metric tons (see for example > http://overpass-turbo.eu/s/cqw ). It may be that Pittsburgh has woken up > one morning and decided to adopt SI units ahead of the rest of the country, > but I doubt it. Logically I'd expect a router encountering "maxweight=10" > in the USA might want to interpret it as "10 US tons" rather than 10,000 kg, > but based on the above I suspect that at least one router isn't going to do > that. > > The relevant wiki page http://wiki.openstreetmap.org/wiki/Key:maxweight does > say "as of September 2014 only metric units of weight (metric tonnes or > kilograms) are supported for this tag". I'm unaware of any discussion prior > to the 17 September 2014 change (not that that means that it didn't happen, > just that I'm unaware of it). > > I'm not from the US, and I'm not sure what the right answer is (if as a > community you're happy entering maxweight=4.5359237 it'd certainly make > everyone's lives easier), so I'm posting this here and then retiring back > across the Atlantic :) > > Cheers, > > Andy (SomeoneElse) > > > ___ > Talk-us mailing list > Talk-us@openstreetmap.org > https://lists.openstreetmap.org/listinfo/talk-us ___ Talk-us mailing list Talk-us@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-us
Re: [Talk-us] Maxweight in the USA
This issue has come up as well with the height of mountain peaks; those of us who hike in the mountains in the US know peak heights *only* in feet, but OSM seems to reflect this in meters; this is entirely unhelpful to local hikers. Us locals think of Sierra Peak as 4050 feet, not 928 meters. The discussion was strictly informal, but I think a number of us liked the idea to support a unit of measure, such as ele=4050ft or maxweight=10t Steve -Original Message- From: Andy Townsend [mailto:ajt1...@gmail.com] Sent: Monday, November 02, 2015 1:59 PM To: Talk Openstreetmap Subject: [Talk-us] Maxweight in the USA Just a heads up... There's a bit of a discussion going on at the moment as to whether it makes sense to store SI units (or actually a derivative - metric tons) in maxweight tags. I noticed a few changes (initially to other values in the UK), and commented on https://www.openstreetmap.org/changeset/35009662 , and the person making a changes (who's the author of one of the popular routers using OSM data) wrote a diary entry here: https://www.openstreetmap.org/user/karussell/diary/36220 . The argument in favour of the change is that storing an SI derivative makes the data easier to consume; my counter-arguments are that (a) it makes it harder for mappers to verify values and (b) anything consuming data shouldn't assume the data is valid anyway (for "Bobby Tables" reasons if for no other). Whilst doing this I noticed that a bunch of other "x tons" weight limits had had values changed a while back (see for example http://www.openstreetmap.org/way/32719427/history ). That's now been changed to "maxweight=4.5359237" which is at least not heavier than the actual posted restriction. However there are still some other integer values without units which implies metric tons (see for example http://overpass-turbo.eu/s/cqw ). It may be that Pittsburgh has woken up one morning and decided to adopt SI units ahead of the rest of the country, but I doubt it. Logically I'd expect a router encountering "maxweight=10" in the USA might want to interpret it as "10 US tons" rather than 10,000 kg, but based on the above I suspect that at least one router isn't going to do that. The relevant wiki page http://wiki.openstreetmap.org/wiki/Key:maxweight does say "as of September 2014 only metric units of weight (metric tonnes or kilograms) are supported for this tag". I'm unaware of any discussion prior to the 17 September 2014 change (not that that means that it didn't happen, just that I'm unaware of it). I'm not from the US, and I'm not sure what the right answer is (if as a community you're happy entering maxweight=4.5359237 it'd certainly make everyone's lives easier), so I'm posting this here and then retiring back across the Atlantic :) Cheers, Andy (SomeoneElse) ___ Talk-us mailing list Talk-us@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-us ___ Talk-us mailing list Talk-us@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-us
[Talk-us] Maxweight in the USA
Just a heads up... There's a bit of a discussion going on at the moment as to whether it makes sense to store SI units (or actually a derivative - metric tons) in maxweight tags. I noticed a few changes (initially to other values in the UK), and commented on https://www.openstreetmap.org/changeset/35009662 , and the person making a changes (who's the author of one of the popular routers using OSM data) wrote a diary entry here: https://www.openstreetmap.org/user/karussell/diary/36220 . The argument in favour of the change is that storing an SI derivative makes the data easier to consume; my counter-arguments are that (a) it makes it harder for mappers to verify values and (b) anything consuming data shouldn't assume the data is valid anyway (for "Bobby Tables" reasons if for no other). Whilst doing this I noticed that a bunch of other "x tons" weight limits had had values changed a while back (see for example http://www.openstreetmap.org/way/32719427/history ). That's now been changed to "maxweight=4.5359237" which is at least not heavier than the actual posted restriction. However there are still some other integer values without units which implies metric tons (see for example http://overpass-turbo.eu/s/cqw ). It may be that Pittsburgh has woken up one morning and decided to adopt SI units ahead of the rest of the country, but I doubt it. Logically I'd expect a router encountering "maxweight=10" in the USA might want to interpret it as "10 US tons" rather than 10,000 kg, but based on the above I suspect that at least one router isn't going to do that. The relevant wiki page http://wiki.openstreetmap.org/wiki/Key:maxweight does say "as of September 2014 only metric units of weight (metric tonnes or kilograms) are supported for this tag". I'm unaware of any discussion prior to the 17 September 2014 change (not that that means that it didn't happen, just that I'm unaware of it). I'm not from the US, and I'm not sure what the right answer is (if as a community you're happy entering maxweight=4.5359237 it'd certainly make everyone's lives easier), so I'm posting this here and then retiring back across the Atlantic :) Cheers, Andy (SomeoneElse) ___ Talk-us mailing list Talk-us@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-us
