Okay, so your point is that since “coach” is defined in UK law already as “a heavy bus”, maxspeed:coach=* shouldn’t be used because it can lead to misunderstandings as the OSM definition of “coach” (a travel-bus, like wikipedia definition) collides with the common understanding for British people?
I’d say that any kind of vehicle that is mentioned in a code of laws is defined some way, and I am absolutely certain that the exact definition *always *differs in one way or the other from country to country. As OSM is an international project, the tags used in OSM are always just a projection from the national definitions. In other words, they always differ if you look closely enough.
While in British law, coaches are defined as “heavy buses”, for example the German equivalent (never called by name) are buses “that have travel seats with seat belts, built for the transport of seated passengers”. But whatever the definition in law, I think we all have a common understanding what a coach is (see wikipedia). So, this is not a problem. Also, we can reasonably assume that car makers build their vehicle types so that they are allowed as this vehicle type not only in UK but i.e. all over Europe.
So, anyway, back to the initial question: Is tourist_bus supposed to be the same as a coach, as it is defined in the wikipedia?
I see that the https://wiki.openstreetmap.org/wiki/Key:tourist_bus refers to a discussion on the tagging mailing list in 2011 - maybe if you find that discussion it would throw some light on what was intended by tourist_bus. It seems to be used as an access key for bus or coach vehicles taking passengers on tours, i.e. not operating as scheduled public transport. So a coach on a scheduled intercity route would presumably not be a tourist_bus, but I suppose would be subject to the “coach” speed limits - which suggests this is not the tag you need.
I looked for it, but did not find anything now (only from 2014, but the tag was documented earlier). Okay, then what I will do is to document “coach” as a subcategory for “bus” and describe what the usual understanding of it is (seats with seatbelts, usually baggage storage below, usually used for travels between cities and so on)
The 7.5 t limit is not what distinguishes a coach from a bus. Note in the document the proviso “except designed for urban use”.
The double-decker buses running on my local route are Alexander Dennis Enviro’s (https://en.wikipedia.org/wiki/Alexander_Dennis_Enviro400) which according to wikipedia weight 18 tonnes. Boris buses weigh around 12.tonnes. I believe the original Routemaster was unusual for an urban bus in coming under the 7.5 t (or perhaps 8 tons pre metric) and thus in the past could be driven privately with an ordinary driving licence.
Quite beside legal definitions, we should use the ‘duck test’ on OSM. The main obvious differences between coaches & buses are as follows:
Standing passengers regularly assumed (I guess that in some cases coaches may take standing passengers, but this is not usual, and may not be legal).
Level access with no steps. Older buses may not match this criterion, but the vast majority of buses used as PSVs will have level access for wheelchairs and the ability to ‘kneel’.
Very limited luggage space.
No seat belts fitted.
No regular standing passengers.
Wheelchair access if available via a lift not roll-on access.
Extensive luggage space, usually under the floor of the passenger compartment
Individual seats with armrests reflecting a generally higher level of fittings. Seats may be reclinable too.
Often with additional facilities: on-board toilet, USB charging points, and on long-distance coaches at seat entertainment systems.
I am no means an expert on this area so there may be more info to be gleaned, but it looks to me on the basis of the above that the distinction really needs to be a conditional weight tag related to maxspeed:psv for the UK.
A couple of local express services, notably the Nottingham-Derby Red Arrow are operated by coaches (Plaxton Elite): I probably could find out how fast they go on the dual carriageway
It is impossible to put the exact legal definitions of vehicle classes into OSM because if we tried to map the exact legal definitions to OSM, we could not work with any already defined vehicle classes like hgv, bus, minibus, motorhome, goods, etc. As I said, it is and only ever can be a projection, not a 1:1 mapping. You have this projection anywhere where you bring together the legislation of different countries, e.g. in this list in the wikipedia you will find a column that includes trucks, even though the exact definitions of what constitutes a truck are different in each country.
So, your proposal is to ditch every vehicle class that is defined because the exact legal definitions in different countries vary, and replace it with what?
Note, if the definition in UK law for coaches is that of buses with a weight of 7.5 tonnes or more, the maxspeed rule in OSM needs to be maxspeed:bus=60 @ (weight >7.5) of course, not maxspeed:coach=60, because the definition in OSM wiki of a coach differs from that in UK law. It makes sense to document that as well when documenting coach in the wiki
Hmm, right, that might be an option. Or is this the default for vehicle classes anyway already?
Anyway, so more or less the definition from SK53 can be taken (adding some “usually” and “in many countries”) and add that in the UK, a coach is defined as XYZ. Extend the article later for more countries, if necessary.
I cannot say anything about coaches in the UK, but was asked by someone on this thread about the tourist_bus vehicle class on the access page. The wording is a literal translation of a sign I found here: https://www.openstreetmap.org/way/100307268#map=16/42.2460/11.7783
The term used on the sign (free form extension sign) was tourist bus which isn’t a category in Italy according to the highway code. Given that there are only 2 types of busses in the wiki, bus for busses operating as public transport vehicle, and tourist_bus, I would expect the latter to describe coaches.
I would not look at weight ratings but rather on the maximum capacity of the vehicle: if it is intended to transport more than 8 people it is a bus.
Is this what you saw on the sign? If yes, I think the proper English word for that type of bus (coach) would be better to use than a literal translation from Italian because in English I would say that a tourist bus is something else (a bus for tourists, perhaps a subcategory of coaches, or sightseeing buses)
You should not add basically unused tags on the access summary page (map features, these are features that are well established and defined). The right way to do it is create a proposal and see what the community says.
In general, we certainly need to express at least 2 different things in the context of busses: special permissions for buses acting as public service vehicle (can use bus lanes, etc.), i.e. the key “bus”, and restrictions for vehicles falling into the bus vehicle class (the key tourist_bus). Even if you argue that tourist_bus does not include psv buses that do not act as a psv, it is still clear that “coach” is a synonym of “tourist_bus”.
In other words, to describe the legal situation in Germany, Italy and likely elsewhere we need this: (tourist_bus, in German Kraftomnibus, in English maybe “motorbus”?)