OpenStreetMap

Help required for adding access information to track roads

Posted by jguthula on 22 July 2019 in English (English)

Dear OSM Community,

At Amazon we are coming across a situation where unmaintained track roads have no access tags. We would like to know your suggestions/feedback on how to tag these roads.

Track Roads:

By definition track roads implies traversal of motor vehicles and are mostly used for agricultural use. We have private GPS traces showing where delivery vehicles go, and when we match them against OSM data, we see they’re going along highway=track ways. We want to add appropriate access tags so that routers can route correctly along the data in the future.

Screen Shot 2019-07-16 at 9 57 15 PM

The driver trace is on-the-ground evidence that the road can be used by motor vehicles for deliveries, but we have no evidence either way that the road can be used for general traffic.

There are four different ways we’ve come up to tag this information:

1. motor_vehicle = yes

Our editing team used to do this, but the community has pointed out that it’s incorrect because we don’t know if the roads can be used for public motor vehicle traffic. This is particularly a problem for track roads that could connect two roads.

Picture1

If the track road were tagged as motor_vehicle=yes, the data would show that anyone could connect from one side to the other. We don’t have evidence on that.

2. motor_vehicle = destination

This indicates that local traffic can go there. Unfortunately, it also says through traffic can’t use it, which we also have no evidence on apart from our delivery partners route information.

3. motor_vehicle = delivery

This is the same as #2, except it indicates delivery only. All public traffic will be blocked from routing via this road.

4. service = driveway + surface = unpaved

Since most of the track roads are leading to independent houses or commercial entities, these track roads can be converted to driveways and add ‘surface=unpaved’ information as per available sources. This might not be applicable to all the track roads but only to roads leading to housing entities and vehicles visible in satellite images.

Our personal preference is the combination of #2 and #4 as we think this correctly captures the information we have.

What do community think is the most appropriate tag for this case?

As per community request, we’ve stopped adding motor_vehicle=yes to track roads and reverted all the changes we made previously in UK while we sort this out. Do let us know your suggestions.

Regards,

Jothirnadh

Comment from Silva1989 on 22 July 2019 at 20:34

Considering your example, a private driveway it could be tagged as:

highway=service service=driveway access=private surface=unpaved

Comment from Rovastar on 22 July 2019 at 21:43

I would be a fan of access=private for this.

I wouldn’t call what looks like a track a service road though.

Each country/region might have different interpretations of the same tags. (sadly one of the problems in OSM when editing across the world)

I’m in UK and I wouldn’t have problem with motor_vehicle = yes and access= private (there might be more seldom used access tags (access=delivery but I would use that for explicitly labelled delivery entrances) but as a catch all private covers most of these).

The fact some in my community made you revert everything speaks volumes….

Comment from Warin61 on 22 July 2019 at 23:09

Where there is no access tag the default value, I believe, is access=yes.

So any tag of motor_vehicle=yes would be redundant. Any tag of motor_vehicle=delivery/destination would be adding a restriction.

The tag highway=track is used by many for any small unpaved roads. If it truly is a driveway then it should be ok to change it to highway=service, surface=unpaved, service=driveway. However some of the ‘driveways’ here can be 100 km long .. I have tagged those highway=unclassified, surface=unpaved, access=private. Note the surface tag, if desired a width tag could be used too.

I would be very hesitant about changing these if they are already mapped. Adding new ones, ok, make our best decision based on what you have.

Comment from yvecai on 23 July 2019 at 05:44

I would be reluctant to add any access=* restriction if there is no obvious restriction. A simple highway=track make perfect sense without other information. Yves

Comment from Nakaner on 23 July 2019 at 18:02

The posting by jguthula was crossposted on the German OSM forum where people have different opinions (published in English) than those voiced here. https://forum.openstreetmap.org/viewtopic.php?id=66880

Comment from RobJN on 23 July 2019 at 19:35

Hi Jothirnadh,

Thanks for sharing this question with the community. I have notified those members signed up to the talk-gb mailing list in case they want to comment.

We have a non profit community company here in the UK. Please see osmuk.org or reach out to board@osmuk.org (I am one of the Directors) should you wish to discuss ideas of how we can both help each other.

Do you collect any street imagery alongside the GPS tracks? Is this something you may want to consider?

Best, Rob

Comment from chillly on 23 July 2019 at 21:09

OSM is about groundtruth - what is really there. We can deduce some geometry from sources such as aerial imagery, but to get detailed information requires a survey. A GPS track is still about geometry - a survey needs more information to be recorded than just a GPS track. Your drivers are not likely to stop to record this information, so you still do not have enough information to routinely use a tag or tags to extend OSM. You could add a note asking people who are prepared to survey the site,or who already know the area, to add tags to help with your problem.

Access tags may not help. A building may have a service road with a ‘private’ sign. The gold standard of OSM (a ground survey) would lead to a tag access=private. Would that help you? I feel that in reality most private roads are accessible to delivery vehicles.

Surface tags would help you understand whether your vehicles could be used on that track. I wouldn’t drive a largish road vehicle on a surface=ground on a wet day, but I’d confidently use a track with a tracktype=grade1 and probably tracktype=grade2.

I’m still a bit skeptical that a set of map tags can completely describe all of the real world situations and trust that a decent driver will work it out best. The CEO I most respected in my working life said to me that everytime we hire a pair of hands we get a free brain that we should always find a way to trust.

Comment from RobJN on 23 July 2019 at 23:20

OSM is about groundtruth - what is really there.

Yes, but there is a second element, namely how you interpret the tagging guidelines. I feel that this is important here.

What Amazon seem to be suggesting us that they do not believe highway=track on its own is correct for routing to deliverable addresses.

Personally I struggle with choosing between highway=track and highway=service in some cases. Looking again at the wiki [1] it states “Roads which provide access to a single property, such as driveways, should be tagged highway=service.” (I think “single” is too string here - it could be a “few”). It also says that track is for agricultural and forestry cases.

Based on this interpretation I’m coming to the opinion that despite a ground truth survey the tagging is probably wrong. If Amazon have a property to deliver too (which they do) and can record a GPS trace (which they do), then my interpretation of the guideline is that the track can be re-tagged as highway=service. I would however leave it at that and not add a service=* any access tags or surface=* as they don’t have recorded data for those tags.

All views are my own not OSMUK’s.

[1] wiki.openstreetmap.org/wiki/Tag:highway=track

Comment from SomeoneElse on 24 July 2019 at 12:41

@jguthula - thanks for asking the question, it’s a very good one.

I suspect that the “correct” answer will vary hugely depending on where in the world a particular road or teack is. You asked in the German forum, and as noted above got a somewhat different answer to some of the replies here. That’s not a surprise - the German answers that suggest to (“rely on official roadside signage”) won’t tend to work in (for example) England and Wales where private roads and publically-accessible tracks may not have that signage. Other countries may need a different answer again - your example is in Canada; I’ve no idea what the best answer there would be.

In terms of England and Wales (which was where this question first popped up), many/most of these tracks will be access=private. Some may be designated rights of right (a “public footpath” implies “foot=yes” in addition to any other access rights that might be appropriate; a “byway open to all traffic” implies “foot=yes; horse=yes; bicycle=yes; motor_vehicle=yes” and there are other designations too). This isn’t OSM in England and Wales trying to make things more complicated than they need to be - it’s the local law; we don’t have anything like the Swedish “Allemansrätten” that presumes access is allowed with certain caveats. Scotland does (that’s why I said “England and Wales” rather than “The UK” earlier).

As other people have already said I don’t believe that you can infer motor_vehicle access tags based on a GPS trace only. All you know is that someone delivering a parcel was able to deliver it there. Given that (as noted above) that would be perfectly possible even if the access was “private”, adding any sort of access tag based on just a GPS trace in England and Wales is a non-starter. What you may be able to do is to decide (based on likely usage) whether it’s a “highway=service; service=driveway” or a “highway=track” (though that can be difficult) and what surface tag would be appropriate (“paved” should be doable from imagery; anything else less so). Other tags that are sometimes used with tracks are “tracktype” and “smoothness” - it would be difficult or impossible to do these accurately just from imagery.

However, as RobJN has already asked above, and as the posters in the German forum already mentioned - do you have the ability to collect any more on-the-ground information such as photography? A ground-level picture of a track or even a couple of questions on the “I’ve just delivered a parcel” job complete form would help hugely at classifying these roads and tracks better. There’s also the “ask a local OSM mapper” approach - there will be places where someone in OSM has mapped something as X and you don’t understand why - you can just ask them by commenting on the relevant changeset.

Best Regards,

Andy (answering in a personal capacity only)

Comment from jguthula on 24 July 2019 at 16:28

Thanks for all the responses. I can totally understand how the road classification can vary from country to country. I have also posted the same content in UK forum (https://forum.openstreetmap.org/viewtopic.php?id=66878), German forum (https://forum.openstreetmap.org/viewtopic.php?pid=756650#p756650) and talk GB mailing list as well. I will wait until this weekend to get more responses from the community members and also to cover as many edge cases as possible. Later this week I will compile all the information from different forums and come up with a list of possible solutions.

Regards, Jothirnadh

Comment from LivingWithDragons on 29 July 2019 at 12:23

chillly gives a good response about ground truth and a “private” sign. Sometimes these can be difficult to spot unless you’re looking out for them. These tracks would be tagged with access=private (although how legal the sign is may be debated, but that’s not for this).

For deliveries, you may want to assume access=private is acceptable to use to get to the destination(if required) as you have assumed-permission. I would not use access=private to take a short cut.

For tracks that connect two roads (short cuts), then enough weight should be applied to highway=track that it’s unlikely to be used (because it would be slower). Additional tags such as surface and track type could be used to fine tune the weighting, but it’s very rare they’re going to be favoured in the UK for routing. Unless Amazon are now delivering using tractors.

Comment from GinaroZ on 29 July 2019 at 20:41

I think there are two distinct categories of service/track roads in this discussion. As mentioned previously, dead end roads/tracks can usually be accessed by delivery drivers even if there’s a private sign. Though even if there is no road mapped, or it is tagged private - routers for delivery drivers should be able direct them to the closest point on the main road.

In cases where the tracks connect two roads, I would suggest an OSM note could be opened at the location if you don’t have enough information to remotely map access restrictions or other details, so local mappers can help.

And in your example of the connecting track “Williams Road”, looking at imagery and Mapillary/OpenStreetCam for that location shows some blocks placed to prevent access at one end, presumably you don’t have GPS data going along the whole track?

Comment from flohoff on 30 July 2019 at 16:02

A track is defined as beeing mostly agricultural. A driveway to a farm is not for agricultural purpose but for living so the tagging as track is broken. There are more Post, Amazon Logistics, parcel deliverys, garbage trucks, School kid transportation etc than there are tractor movements.

So tracks which represent the only way to housing or the primary access to housing should be retagged as service/driveway. If not asphalt probably with different surface tags.

Flo

Comment from flohoff on 31 July 2019 at 07:56

BTW - Slapping an access=private to all driveways makes them unroutable. Its a bad habbit IMHO to tag access restrictions where they are not explicitly signed.

I call that “felt access restriction”. As OSM maps things which are verifyable on the ground we should NOT tag every driveway with access=private.

I am doing analysis on “non-routeable” addresses for example Nordrhein-Westfalen a part of Germany and we have TONS of addresses which are more than 500 to 1000m from the next legal street to use although they have a driveway which is legally not usable by the access=private

Flo

Comment from Warin61 on 31 July 2019 at 10:23

I don’t think driveways are seen as access=public. Possibly access=destination?

Other areas of the world? Some remoter places ? Some ‘driveways’ have more ‘agricultural use’ than ‘living’. Some places have the mail delivered by plane.. once a week, together with some groceries. https://www.abc.net.au/news/2018-05-06/great-australian-flying-outback-mail-service/9701182 Garbage trucks? No. These places have there own dump for garbage. Amazon, DHL, FedEx etc etc.. no .. they simply don’t get to these places.. they have to go pick things up ..usually they go by plane, there own small private plane. Just as most people learn to drive, people out here tend to learn to fly.

Comment from flohoff on 31 July 2019 at 10:30

@Warin61 - The tagging as service/driveway already says its not a public road. Thats enough. Any access restriction which is not explicitly verifyable by a sign, gate, fence or something is broken.

We do not map/tag anything which is not verifyable with the great exception of boundaries.

And show me one driveway which has more agricultural when people are living there. I am myself living in the middle of the woods with a rough road of 2km as the only access.

As soon as people are living there you have 2 car usages per day for people going to/from work. Show me a track where there are more than 400 tractor movements a year.

And we are not talking about delivery by plane but places where Amazon Logistic goes with the delivery vehicles.

Flo

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