There is no right answer. If you tag things 40mph (which is what I do, like most of the other people who've replied) then you may well find that someone else goes round systematically changing them to km/h and puts in maxspeed:mph - that's what's happened to most of the ones I've done. I think it's being done with an occasional bot enforcing one user's opinion over the original mapper's.
Given there are, as usual, as many opinions as there are contributors, and the rule we have, unfortunately IMO, is that there are no rules, the only way this will be solved is for consumers to understand all the reasonable variations. I also came across someone tagging maxpeed=NSL yesterday. If it gives someone happiness, fine, but I don't really think it should be necessary to tag the default situation, only when there is an exception to the general rule. David On 04/06/2009 10:49, Dave Stubbs wrote: > 2009/6/4 Peter Miller <peter.mil...@itoworld.com>: >> I have been looking at the coverage of maxspeed limit data for highways in >> the UK and we seem to have a right mix of styles. >> Here is the data for bug chunk of England while avoiding including anything >> from France or Ireland (which would include km/hour figure). We current >> have over 17,000 highway ways tagged with maxspeed and also 300 ways tagged >> as 'maxspeed:mph'. You will notice that for 30 miles per hour we have 30, > > > You're assuming that's not a 20mph limit expressed in rounded down kph. > > >> 30mph, 30 mph, 48.2, 48.28, 48.280, 48.27808, 48.28032 and 48.28. >> Any suggestion on what we should recommend for the UK? I guess the USA >> should also be party to this discussion but they have far less population of >> the maxspeed field (only 70 uses in the Bay area) so possibly we should come >> to a view first. Our options seem to be:- >> maxspeed=30mph (the user should strip a trailing mph to find the value) >> maxspeed=30 (leaving it for the user to realise that it is in the UK and >> therefore imperial) >> maxspeed=30 mph (the user should strip the last word if it is mph including >> the space) >> maxspeed:mph=30 (Easy for the user) >> maxspeed=48.28 (with a defined precision) For metric use no work by the >> user, for imperial use a look-up table is required or a conversion and >> rounding > > Meh. 30mph == 48.28032 ~ 48.28 ~ 48 (and is what the highway code says). > Any of those as tags will do for most purposes. The only one I'd > complain about is specifying a mph value without the unit because it's > impossible to determine what was intended. km/h is common enough to be > used as the default. > Whitespace is trivial to remove. > > FWIW highway code conversions are: > 20mph = 32 > 30mph = 48 > 40mph = 64 > 50mph = 80 > 60mph = 96 > 70mph = 112 > > Dave > > _______________________________________________ > Talk-GB mailing list > Talk-GB@openstreetmap.org > http://lists.openstreetmap.org/listinfo/talk-gb _______________________________________________ Talk-GB mailing list Talk-GB@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-gb
