On 12 November 2013 18:16, Pee Wee <piewi...@gmail.com> wrote: > Together with user Masimaster I've made a proposal for a new tag to improve > bicycle routing. I think (and hope) the wiki is clear enough but I’ll say a > few words about this new tag. > > The tag is introduced to separate 2 kinds of roads where you are not > supposed to ride your bike.
I'm afraid I'm not convinced by the proposal at https://wiki.openstreetmap.org/wiki/Bicycle_use_cycleway . First of all, the proposal is not clear on exactly when this tag is to be applied, in some places you say it's to be used when there is a parallel "compulsory" cycleway, and elsewhere it says "official". Then use of "allowed / wise" also introduces ambiguity as to whether the tag is intended only for routes where most cycling is banned on the road, or just when cyclists would generally choose not to. This needs to be clarified. (In the UK for example, we often have cycle tracks running parallel to the road. There is also an official government document called the "Highway Code", which includes the clause for cyclists: "Use cycle routes, advanced stop lines, cycle boxes and toucan crossings unless at the time it is unsafe to do so. Use of these facilities is not compulsory and will depend on your experience and skills, but they can make your journey safer." It's not entirely clear from your proposal whether or not the proposal means all UK roads with parallel cycle routes should be tagged with bicycle=use_cycleway. I would presume not, but I think the proposal as written is open to interpretation.) Secondly, you mention the case of special types of bicycle eg tricycles. I would argue that if such vehicles routinely have a different legal status with respect to access rights in a particular country, then they should be given a more specific access tag key to over-ride any access tags set for bicycle. This is how we handle other access issues where certain types of vehicle are an exception. (For example, on a service road only open to buses and taxis, we would set vehicle=no, psv=yes. Here we should use something like bicycle=no, <special-type-of-bicycle>=yes.) Finally, I think that it is not a good idea to introduce an access tag value where the precise effect is going to vary by country and have different meanings to different people. IMO the access tags should be used to express absolute states as well as possible, rather than being subject to different interpretations in different places. Routers etc shouldn't need to know about different national laws and conventions to interpret the main tag. (This is why, for example, we tag national speed limits with a numerical maxspeed=* tag, and then provide a supplementary maxspeed:type=* tag to explain how that numerical value is derived. Or why in the UK, we tag access rights such as foot=yes in addition to the legal origin of those rights e.g. designation=public_footpath.) So I would suggest that on any roads where cycling is generally disallowed, we continue to use bicycle=no as the standard tagging. If certain sub-types of bicycle are allowed, then an additional access tag can be added to override bicycle=no for those cases. To express the legal origin of the restriction, and provide the information to routers that want it, I'd suggest adding tag along the lines of bicycle:restriction_type=DE:use_cycleway where the value comes from a country code and a table of values that list the various legal statuses that may exist in each country. This has the advantages of (a) using a backwards compatible bicycle=* value (b) allowing users/routers that don’t want to be bothered with the details of different restrictions to give a reasonable result that will be right in most cases, (c) providing a standard way to record the precise legal status of the route, (d) allowing routers that do want to be bothered with the details to implement them on a country- and law-specific basis. None of these advantages are present in the original proposal. If there are cases where it is less clear cut that cycling is generally forbidden, then maybe a more generic tag of bicycle=restricted might be better as the main tag, again in conjunction with a separate tag to identify the precise restriction that applies. (Yes this will mean the main bicycle=* tag needs to be interpreted by routers, but at least it gives them a single generic tag for "you probably can't cycle here, but you need to check for details" which they can use to warn end-users if the router doesn't want to work out the precise details themselves.) Robert. -- Robert Whittaker _______________________________________________ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging
