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 <[email protected]> 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 > [email protected] > https://lists.openstreetmap.org/listinfo/talk-us _______________________________________________ Talk-us mailing list [email protected] https://lists.openstreetmap.org/listinfo/talk-us
