Does Maxspeed = Road Speed Limit?

Simple question really, does the ‘Maxspeed’ mean the road speed limit. I ask because this is very useful data to have, and to be correct! I’ve only just noticed the option today.

It would be useful in Potlach that when you select the road type (residential, motorway etc) that as well as the name field automatically showing that the maxspeed also shows. In recent discussions at pocketgpsworld.com it was mentioned that OSM is lacking severely from the commercial providers because it doesn’t have road speeds - where as it seems it does (but not very well advertised!)

If someone could confirm that Maxspeed should be used as the speed limit then I will let them know at pocketgpsworld.com and get them all updating again!

MaFt

Yep, as far as I am aware the maxspeed key is indeed for the maximum legal speed. I’ve been using it for that anyway. Minspeed is also a useful thing to record if there is such a limit.

Yes, maxspeed=* is for road speed limits.

And coverage is spotty, but not non-existent: http://maxspeed.openstreetmap.nl/ & http://maxspeed.osm.lab.rfc822.org/ show the situation for BeNeLux and Germany respectively.

maybe if it is shown in potlach when a new road type is added/edited then more data would be added? i only discovered it by accident earlier…! i.e. when i add a new church i get amenity (place of worship), denomination, name, religion (christian) as fields that show up as default values - i see this as being an expected minimum amount of information. if the same happened with roads eg you choose ‘primary road’ and then you get highway (primary), name, ref - why not also maxspeed? i think the name, reference and speed are probably the more important bits of information to have for each road?

MaFt

Name/ref are very important for almost every use case (searching addresses, route descriptions, orientation on printed maps…).

Maxspeed, on the other hand, just isn’t that important. It’s largely irrelevant for pedestrians and cyclists, and for car routing it can only lead to small improvements - in most cases, using shortest paths combined with the highway=* values will provide sensible results. Restrictions such as access and oneway tags, maxheight/-width/-weight, but also turn restriction relations are much more important than maxspeed, imo, because they can make a route completely inaccessible, not just less desirable.

Maybe that’s because most roads have the default speeds for their highway=* type and therefore don’t need a maxspeed tag at all?

That depends greatly on the country in question, and what mappers in that country have decided to do.

For the first remark: it’s very (imho too) common in NL to turn roads into 60km/h where 80 is default, and 30km/h where 50 is default (and 100 vs 120). Which in turn means: lots more data to put in, and for good measure I personally also then put in the default when I have the time to do so.

The seconds is an interesting one. What people have decided to do. Some may just tag every speed they find, explicit and implicit. Others may resort to ‘creative’ tagging like maxspeed=DE:city or maxspeed=AT:urban.