Proposal:Use sideway arguments

This is an extra page to the use_sideway value.

Extra info about the last proposal (bicycle=use_cycleway) and some of our arguments

We saw, that the definition of the last proposal (bicycle=use_cycleway) was not clear enough and left some room for interpretation. We forgot to express that basically this tag is an "access" issue. We also forgot to express why and in which cases it can improve routing.

Reasons for opposing

There were quite a few reasons voters opposed. Here's a list of what we think were the main reasons why the old proposal was opposed:

1. Some believed it will not improve routing.
2. There is no need for a new tag because routers should know that cycling is not allowed based on the fact that there is a compulsory cycleway that is parallel. If we make a new tag it is "tagging for the router".
3. bicycle=no is in use and could/should be applied here.
4. there is no sign on the road: no sign->no tag
5. no backward compatibility to the existing bicycle=no (in e.g. NL)
6. bicycle=destination could solve the problem.
7. bicycle=restricted could solve the problem

Our view on these items are:

1. It is an access tag, like many others. Even if you are convinced it will not improve routing it should not be opposed just because of this reason.
2. Again, it is first of all an access tag.
3. bicycle=no is not the right tag because it is not a "hard" no hence the absence of a "forbidden sign". In some countries special bikes or groups of race bikes are allowed on the main road when there's a parallel compulsaory cycleway. Also in some countries an ordianry bike is allowed on the main road when there's a specific situation which makes it impossible or hard to use the cycleway. Like snow, parked cars or otherewise unsafe situations. So bicycle=use_sideway is something in between a YES and NO like "destination, limited, restricted".
4. In some countries (like NL) the parallel cycleway is legally considered to be part of the main road. In that sence the sign Compulsory cycleway says something about both the cycleway and the main road.
5. As far as we know there is only a backwards compatibility issue in NL. Except for NL the roads we are discussing do not have a bicycle=* tag yet so we see no issue here. To keep backward compatibility in NL, we can agree not to retag (no->the new tag) for some months/a year. It makes sense to add a temporary taging in NL like bicycle:no=use_sideway, which can be automatically transformed to the proposed tag after the interim time. If the voting is accepted, we can inform the router-engineers about the new tag, so they have time to implement it to their software. There has already been a demand for this kind of tagging by a router (BRouter).
6. Bicycle=destination is used in situations where normally you're not allowed to ride your bike there unless this is the more or less only way to get to your destination. The proposed tag is meant for all roads next to compulsary cycleways regardless of beeingclose to your destination. Using bicycle=destination instead of side_way would make destination a useless value.
7. bicycle=restricted is too general and does not give any information about WHAT the restriction is and WHY there is a restriction. Use_sideway implies that there is a compulory cycleway which gives information about WHY there is a restriction. Together with a country specific access table one can conclude WHAT the restriction is.

What key/value should we use?

In the discussion on the old proposal some suggestions were made for the key & value (tag):

1. bicycle=use_cycleway (= old proposal)
2. bicycle=use_sideway or bicycle=use_sidepath (it could also be used for foot=*) (= new proposal)
3. bicycle=no combined with a new key/value like bicycle:no=use_cycleway or bicycle:restriction=use_cycleway or bicycle:use_cycleway=yes
4. bicycle=restricted + bicycle:restricted=use_cycleway
5. bicycle=restricted
6. bicycle=destination

What have we learned from the discussion about last proposal?

1. We'll emphasize on the Access part of the proposal.
2. The VALUE will be more general (use_sideway) and not bicycle-specific (use_cycleway)
3. We've added examples of how it could improve routing and rendering.

Distinguish between roads that are "forbidden" for cyclists

Here are 2 examples of types of roads on which you are not supposed to ride your bicycle.

Type1: This is a road with a bicycle forbidden sign like

Type2: This is a road with a classification that allows cycling on but because it has a parallel compulsory cycleway (like in NL and DE) it is not allowed to ride your (ordinary) bicycle.

Legal authorities have made a difference between this 2 types. Why? In some countries the difference has implications on special vehicles. For example in NL a three wheel bicycle/tricycle with certain measurements is allowed to ride on the type2 road but not on type 1. In Germany there is also a legal (and access) difference between these roads.(read links) In Austria training with a race-bike is allowed on the road. (These Exceptions could be handled by the Country specific access table) In order to allow routing and rendering for different vehicles/purposes we have to distinguish between the 2 types. The question is, how?

How to distinguish between the types?

There are roughly 2 ways to distinguish.

Option A: Tag type1 with a bicycle=no AND tag type2 with a new tag such as the proposed bicycle=use_sideway

Option B: Tag type1 AND type2 with a bicycle=no AND additionally tag Type2 with "my special vehicle=yes" in which "my special vehicle" could be every description of vehicle that is allowed to ride on type2 roads.

Option B means that we are tagging legal matters in OSM and not what we see in reality. Option B means that every time the law changes but traffic signs do not we have to change tagging. Option B also means a growth in the number of tags which does not help to keep things simple and keep overview. Option A does not have these disadvantages.

One could argue that option A (bicycle=use_sideway) is also a legal thing but if we just agree upon the meaning of this tag it is not. bicycle=use_sideway means: This is a road with a classification that allows cycling without a "bicycle forbidden sign" with a parallel compulsory cycleway on which you are supposed to ride your ordinary bicycle. This can be objectively seen in reality.

Universal way of tagging

In NL the type 2 roads are forbidden for ordinary bicycles (a "hard NO"). For this reason they are tagged with a "bicycle=no" The Type 1 is also tagged this way which currently makes it impossible to distinguish between the 2 types. We have to distinguish in order to allow routers/renderers for special vehicles.

Instead of this bicycle=use_sideway we could use bicycle=no an additionally a “my special vehicle/situation=yes”. There are a few reasons why we do not think this is a good idea.

1 Mappers are no legal experts

In OSM we rely on mappers and not legal experts. An ordinary mapper does not know what the legal status is of many extraordinary vehicles and there are many. In NL 3 wheel velomobile with such measurements is allowed to ride these type 2 roads (but not the typ1). Hardly anyone knows this. We're also sure that most mappers don't know the legal status of horse carriages, skateboards, sedgeways, 45km/h pedelec etc. The problem is that there are no traffic signs with pictograms for all these exceptional vehicles so how should a mapper know?

2 Too many tags

Imagine that all special vehicles and situations would be tagged. How would we see all these tags in the editor. We're afraid it would be a complete mess in OSM. Simply too many tags so we loose overview. We are facing enough challenges with the current list of land-based means of transportation.

3 Changing law needs changing tags

Imagine that in NL law would change in such a way that groups of race-cyclist of more then 10 are allowed to use the type2 way. Or maybe the newly introduced fast electric bicycles that do 45km/h are allowed to use the type2 way. Then this would have to be mapped. Who is going to do this? If we would have the bicycle=use_sideway nothing had to be changed. We think we have to be careful with mapping legal access in OSM unless the traffic signs are obvious. In fact we think that if we map in such a way that we (and routers/renderers) know what traffic signs apply to roads, routing for any vehicle should be fairly easy.

4 Country specific

All the exceptional vehicles and situations vary from country to country. Imagine tags like “three wheel bicycle wider then .75m=yes” in NL and “three wheel bicycle with combustion engine > 250Watt=yes” in an other country. This is just going to be too much for most mappers. I would not start mapping these exceptions abroad because I just don't know all legal aspects. Instead a country specific scheme can be made to express access rules of various odd vehicles on compulsary cycleways and their parallel roads.

5 In short

Mapping this way will never happen in such an extend that it will improve routing for bicycles (both ordinary and exceptional ones) .

So all this made us feel it was an illusion to improve bicycle routing by adding different tags for all these exceptional vehicles/situations. This could work in theory but it simply will never work in practice

So, it had to be as simple a possible. Something any mapper could see in reality based on traffic signs and roads and cycleways. That's the reason why we have added a definition of the tag.

Bicycle=use_sideway means:

This is a road with a classification that allows cycling generally without "bicycle forbidden sign" but with a parallel compulsory cycleway