User:Bkil/OSM accessibility initiative

From OpenStreetMap Wiki
Jump to navigation Jump to search


OpenStreetMap had always advertised itself as the only map in the world with accessibility as a priority and the possibility of extending it with whatever information its users would need. The aim of this initiative is to follow up on this promise by delivering as much value of public interest for the said groups as rationally feasible.

We feel that users with mobility and dexterity impairment are somewhat covered by existing tags and tools, so we will first focus on those with visual impairment. However, in case of touching upon objects and tags that can serve multiple demographics, we will review the state of other accessibility issues and suggest small improvements for other accessibility concerns as well.

The intended readership of this live document is software engineers and mapping experts. Content for users will be made available separately and still needs to be written by volunteers.



Chat to people. Answer questions regarding the initiative. Collect ideas and concerns from mappers, engineers and users about the initiative. Communicate with upstream & downstream projects. Feed condensed and filtered communication towards the members within the initiative. Attend the incoming backlog area of the kanban board.

Documentation for engineers and mappers

Review, update, clean up, refactor and extend relevant articles on the OSM Wiki to allow for others an easy overview of the state of the art.

Try to improve the receptiveness of existing mappers of both new and existing tags that can help those with accessibility needs. Many well defined existing tags are underused due to it not being obvious or popularly advertised how useful it can be to others.

Identify FOSS data users

Enumerate all copyleft data users that can be impacted by tagging scheme changes (tools, QA, maps, navigation, etc.). Include both general purpose ones and ones specifically catering to the needs of the target audience. Describe its exact purpose, the tags it uses and anything that could be reused for inspiration in the greater ecosystem. Mark whether it is dead or alive, i.e., whether they need to be consulted with for changes.

Research competition

Enumerate each mapping and navigation app and service that caters to the needs of the target audience at any level, both free and commercial. Review, test, install, watch videos on and precisely document what and how each of them implement this. Note what is missing from their existing implementation.

Interview target audience

Look up past conversations in public forums. Talk to them in person or over chat platforms. Record, transcribe and later analyze in detail how they use a FOSS or competing app on the field. Identify common real world use cases to solve. Find correspondence between existing tags and possible desires which are not covered. Document an incidence rate of each.

Designing new tagging schemes

Extend existing tagging scheme. Follow the OSM way of tag genesis. Come up with new keys and values as needed. Attempt to maintain compatibility and fallback for existing data users. Follow the existing tag proposal process.

Help data users follow up on a tagging scheme change

Find out which data users can be impacted by a given change. Offer to invite their stewards and engineers to the ongoing tagging discussion from the start. After a scheme is settled, open an issue, linking back to the new scheme. After consulting with the stewards of that project about implementation details, complete, document and upstream the change to fix the issue.

Tools for mappers not impacted by accessibility issues

Many existing tools used by mappers support easy customization of how OSM data is displayed (e.g., CartoCSS, filters) and edited over a GUI form (e.g., presets). Converge presets between different tools so the subset of fields should be comparable. Implement new presets as needed by new tagging schemes started by the initiative.

Tools for mappers impacted by accessibility issues

Disabilities are underrepresented among mappers. This causes a skew in both what we map and how. Allow volunteers both on the field and in an armchair to review data in any given area, and discuss it with others, ask for surveying or optionally a sighted second reviewer and apply fixes themselves. Add new objects and geometry.

Tools for users impacted by accessibility issues

Real-time routing & navigation apps. Access all functions from a mobile and through a web site as well. Print routing and navigation instructions with braille for offline unplugged use. Possible visualize select small sites with 3D printing. Geolocation. Allow discovering POI and navigation anchors in the immediate surrounding or at any remote area when planning the route. Allow to share a route or waypoints with others. Reporting map errors in a structured way after logging in with an account. Contributing this way is less scalable, so in collaboration with the user documentation project, encourage upselling person from user to mapper.

Marketing for non-users

Produce documentation, storyboards and scripts for multimedia materials that could encourage everyday people possibly adjacent to the target audience to try OSM-based solutions. Introduce the relevant parts of the OSM project itself briefly.

Documentation for users

Enumerate OSM-based apps & services that cater to the target audience. Generate unified introductions and guides for them. Identify use cases to cover. Highlight in a clear comparison how each solution covers the given use case compared to each other and to the commercial competition. Encourage contribution.

Documentation for helpers

Helper handover (When the helper parts ways with the assisted person, they should negotiate a point to anchor to. The helper should also ask a third party to take over the role of assistance.) Escalator. While you walk together, talk about their problems and introduce OpenStreetMap to them. Politely offer to hand out a Braille-carved OSM business card with a QR-code (containing a URL to a guide and a few keywords as reminder) or flyer if they are interested.

Documentation for mappers

Enumerate tools to extend and fix the OSM database that focus on the target audience. Describe in detail presets and other settings that are crucial for this.


Please add yourself to the following list if you could give a hand with any of the above projects. You should list your focus areas after your name in decreasing order of preference. Volunteers listed here are encouraged to edit this page and subpages under it. The initiative can not be successful before reaching 10 active volunteers.

  1. User:bkil: project management, tagging, consultation when others are stuck, hint at where to patch existing architecture, review source code in any programming language, basic web accessibility, collaborate with groups for the visual impaired in Hungary, organize a mapping party
  2. User:mahdi1234: local interviews/ideas (Czech), maybe some QA tools later
  3. User:RobinJulien: tagging, local interviews/ideas (Belgium), app development (On Wheels app)
  4. Msm1: tagging, tag designs for the blind and partially sighted, tester of navigation applications for the visually impaired, transport, orientation in accessibility
  5. ...

We should create a new mailing list, forum topic, IRC channel, XMPP MUC, Matrix room for discussions, but let's wait for that until we have enough volunteers to kick it off. Until then, you can reach us here:


Could you summarize the initiative in 20 words

Empower blind micromapping with software and tags: they know what is best for them. Educate others to collaboratively deliver value.

When will this initiative begin

Our initial goal is to gather at least 10 active volunteers who can dedicate a small, but predictable amount of effort in whatever area they are interested in. The threshold would be higher if we assumed some with less free time on their hand would join.

It would be best if all stakeholders were present and voicing their opinion as early as possible. They could thus influence the direction taken by the project. It may also reduce the probability of hitting dead ends.

That said, existing volunteers have already started conducting interviews with those of accessibility needs and noting down all possible workarounds they could think of. We go through the notes of each other and try to come up with answers and action points proactively as they come up.

Could you change X and Y

The main aim of this initiative is to interconnect all peers willing to work on specific issues in the same area together, helping one another. The question would be better phrased as would you be willing to make that change? And the answer is definitely yes: join our initiative, sync with us and then you can help out in whatever way is convenient for you. Telling others what to do (perhaps even receiving multiple, conflicting instructions from different outsiders) without getting any skin in the game does not scale, so we would like to pass on that. A group of motivated individuals can only accomplish their tasks efficiently and on the long run if all stakeholders are in-group and if as much out-group noise is filtered out as possible.

How much time do I need to dedicate

You are still welcome if you can commit to allocate just 1 hour every week on this noble cause or just spend a hackathon weekend on narrowly targeted improvements!

Can you sign me up lacking a wiki account

Unfortunately, the ecosystem relies on creating user generated content for others. This can be for example grooming, creating or translating documentation. Even if the roles you volunteer for would not involve any form of documentation, it would still be desirable if you could vote on the adjacent proposals submitted by others in the team - this just involves answering to comments and copy & pasting a single line of voting template to show your approval for others.

I am already part of another initiative

We welcome collaboration with similar and adjacent initiatives. Let's align our goals and even possibly share some of our responsibilities and tasks, perhaps reducing overheads along the way.

Why not in main wiki namespace

This document is in a drafting phase, to be changed by both previous and new members of the initiative as we go. Once we have all agreed on an action plan and are ready to go we can move it to the main namespace and link to it from other existing wiki articles.

Why create new tools

Improving existing tools such as StreetComplete, OsmAnd and the website itself could well be within scope (as long as developers of said projects agree with our additions).

How can the visual impaired do mapping

Not everyone is expected to be able survey everything. Visual impaired users could just as well find new benches, bins and steps (or even measure their size and material) and then add it to OSM. A potential wheelchair user could then later extend those with their colour, model number, reference identifier and finally you may be able to use those objects yourself as intended. OSM is all about teamwork!

Why are the tasks so vague

As this is a live document, we could negotiate and we welcome all contribution. Basically whatever you are qualified to help in and would do it with a warm fuzzy feeling would be a great addition, just shout out! Tried to leave as much of the implementation details open. So after the 10 founding volunteers join, we can then sit down to finalize our methods on a meeting and then a documentation volunteer can rephrase and update the wiki page.

Who are we

It's just you and me! It is a group of random mappers who know visual impaired users personally. Despite supporting this initiative, I'm not sure how committed they might be to participate due to real life reasons, so to honor the work-life balance of others, we aren't signing up people and instead wait for them to decide to join. Most of them are local, but we're just gauging the interest in this internationally and hope for the best. According to my experience, many of the great and extensive projects in this area in the past have concluded in one way or another, hence maybe members of former initiatives could decide to migrate as well.


Below are just some work in progress notes to be refactored to separate subpages after its bulk exceeds 10 pages. Don't worry about it, just ignore it.

Topics for interview

Introduce OpenStreetMap and compare it to other map providers. Tell them about the separation between data and presentation. Enumerate existing tags in the database that they may find relevant.

Map notes, open registration & direct map editing. Enumerate types of data users: mobile navigation, web map, POI overlays, queries for experts, open API. Apps that require an online connection to show or cache vs. one that can work fully offline. Jumping to address, route planning, revealing POI.

What would a visual impaired user find useful to have in the database? How do they navigate with a cane? How do they navigate with a guide dog? Is there a difference in strategy between areas they know well compared to where they have never been to in the past? How do they navigate with existing apps? Are there any specific problems they could name in existing apps? What would they find useful in an ideal future app?

App testing

Install and set up all OSM-based apps on the device of the researcher. It would be even more informative if each subject could agree to install each app on their own device. The whole session could then be recorded including finding the app and setting it up. Travel to the starting point in the respective environment. Launch screen and sound recording and ask the volunteer to accomplish each scenario.

Possible environments to go through:

  • indoor: mall, government, education,
  • in a pedestrian zone,
  • nature,
  • on city sidewalks,
  • on suburban sidewalks,
  • roads lacking a full length of sidewalk.

Possible scenarios:

  • Plan a trip from a random home address to a shop given by name and then return to the home address.
  • Given a list of shops to visit, plan an optimal route.
  • Visit the nearest water tap, bench, rain cover, air conditioned public access building, swing, seesaw.
  • Plan a few kilometer long trip from a well served public transport stop through a dedicated hiking route finally arriving at another public transport stop. The route should have a sufficient amount of forks in the road and crossings by other routes.
  • You are dropped off at a random location within a city. Find the nearest home address and walk towards the nearest visible outdoor location where it is safe and legal to park by car. Imitate a phone call where you dictate how to find the exact location for a friend to pick you up by car or a tandem bicycle.

The researcher should choose a trip that contains an example for each existing OSM tag and that is known to be completely mapped in OSM. Edit the neighborhood before the research to finish it up.

Accessibility tags for the visual impaired

Decorative flower plant pots

  • max_height=*: highest height from the surface to the tip of the plant
  • pot:max_height=*: height of the rim of the pot of the plant, good to know with regards to tripping hazard, discovery by probing cane or hand
  • pot:diameter=*


Determine the colour, shape, size, angle of an object or parts of it using the camera of the smartphone during a quest.

Handout material

Business card

should contain a QR code on both sides that would include the name, web site and rough profession of the owner

may contain the domain name in big Braille letters


Missing tags

New tagging schemes should be engineered to accommodate the following use cases.

Remote controlled crossing

Clear up tagging of orthogonal concepts. Does it activate always, on button press or via a remote? This may be a different button than one that requests a pedestrian to cross. Allow marking of idle state (no-go) vs. go. Does it beep or talk? Which kind of device/remote is it?

Pole tension cables and posts

One or more stakes are driven into the ground and a wire is fastened between them and a power pole or street lamp. These pose a tripping or chopping hazard. Depending on how high the wires are attached, the angle of the wire can be computed or perhaps they might be otherwise approximated by a bounding box.

Two-legged poles

A pole design for lamps and power cables exist which has two legs leaning towards each other with a possibly large gap between the two (perhaps up to enabling a person to fit through).

They may pose a tripping hazard or for bumping your head into.


Thorns, spikes and needle leaves can damage clothes, skin or wheels. They may be soaking wet after rain, making our clothes wet.

Kind: soft leaves or vines that only touch or hard woody parts and branches that hurt. Hedges highly trimmed to a given shape expose more sharp, fractured woody parts that can be less pleasing to touch. If a hedge is not trimmed to a shape, leaves are on the perimeter.

Whether a young tree is secured by rope to stakes or posts, their material and height.

Hitting hat off or head in low hanging branch.

Bush on left or right knocking sandwich or ice cream out of hand.

The origin of the foliage may either be from public property on the left or right hand side of the sidewalk or leaning out from private property through a chain link fence.

If on public property, it may either form a thick bush to protect from ongoing vehicle traffic or a bicycle lane or it may be sparse enough to step through. visible or not, scent even if invisible, sight even if can't touch

Rainwater outlet

Runoff rainwater collection systems installed on the roof usually have outlets facing the sidewalk. They can protrude for at least 10cm, catching the cane when following the edge of fence and walls.

They may be lead into a trough formed across the sidewalk that can be covered by either a different surface, a grill or nothing at all. If uncovered, the width and depth of such trough may be good to know. The properties mentioned for manholes apply to grills as well regarding protrusion and stability.

A different design conducts it through an overhead tube that has a support post just on the other side of the sidewalk, also probable by cane.

In each case, flowing of water can be heard in the rain and possibly flowing of water itself might be observed, especially where the sidewalk is not completely flat and has depressions or waves along its length.


Include relative position of each object. May be substituted with a concrete cube. height=*

Wind resistance

As one is walking past obstacles during a steady light breeze, the change in intensity and turbulence of the airflow can be sensed on the skin.

It is easy to detect the material of a fence nearby the sidewalk, interruptions by gates, street cabinets, hedges and intersections of streets where buildings end abruptly this way.

The difference may also be audible as well. The sound may be caused by resonance effects of the material and its thickness and its interactions with turbulence such as for vegetation or the sharp edges of a tent garage roof. The sound may be caused by higher level mobility when the object has inherent degrees of freedom such as for a flagpole, windchime, small rooster wind vane or an outdoor seating cover made of sheets. Or its bolts & nuts or welding may have gotten loose such as for an advertising board.


  • Steps: as one is walking on it
  • Escalator
  • Elevator
  • Hair drier
  • Pneumatic, powered & hammering screw driver, welding: such as used by a car repair shop
  • Doorbell & intercom phones: you may recognize the melody used when it rings and when it is idle, its speaker or magnet may be clicking (>1Hz), hissing (few kHz), buzzing, hiss (white noise) or drone (50-60Hz)



A surface may be heated against frost or underground heat pipes may radiate waste heat that allows snow to melt above it.

A duct may be venting hot or cool air. This is independent of whether it is audible or not. This might be even easier to notice during indoor navigation.

Radio signals

The radiation of Bluetooth and Wi-Fi networks installed at surrounding shops can be used for indoor navigation where GPS signal reception is usually weak. Some security cameras also broadcast a network name that guests usually can not connect to.

Recording the wireless network name is beneficial for multiple reasons. The name can be stored in internet_access:ssid=*. A guest needs to know the network name (and password) to ensure they connect to the correct network. It can also be used to automatically track whether a shop goes defunct or changes owner.

Precision could be improved if we also noted down the BSSID (MAC address) of the device. It may allow to differentiate between multiple access points. However, access points are usually not mapped as independent nodes at the moment.

Sign plates

Some have a face attached lower than head level. This can either be near the base to indicate direction of avoidance or head-first if it is a less standard sign meant for pedestrians, cyclists or private residents.

Some may have become unreadable or even missing their plate. The post is still useful as a navigation aid, something to resurvey later or infer their effect. Advertising boards and traffic signs should possibly be mapped according to a related scheme.

We could count the number of stakes (or posts) it is standing on. They are usually attached to 1, 2 or 4. The intersection of its posts may be columnar, square or rectangular. Its diameter can also be measured. They can be useful to lock your bicycle to, but not all chains are long enough to reach through if its diameter is too large.

The face can still pose a hazard or provide as an id if a sign plate is attached to a street lamp or power pole.

Surface finish material of objects

The material that compromises most of an object by weight is can usually be estimated when casually probing by cane or knocking on an object by hand.

In contrast, the surface finish itself can be independently estimated based on thermal conductivity (i.e., whether it is a "cold" surface) and texture. For example, a metallic sign might be painted and finished with lacquer.

Most man made materials are composite or alloys whose composition can not be easily determined casually without consulting the data sheet. An uncoated metallic surface may rust over time that is hard to the touch and may even cause damage to the skin.

Manhole cover protrusion

A cover may be either nominally in level with the surface of the sidewalk or road, it may protrude or slump slightly. This may be detected for navigation and may present a slight hazard, especially when icy. Such difference in height usually does not exceed 1cm, because it would otherwise be fenced off as an imminent danger.

A possible way to tag it might be cover:max_height=-0.01;0;0.01 without going into a great deal of accuracy.

The shape of its surface may be smooth (polished metal), asphalt (fresh, usually blends in with the sidewalk), paving stones, rugged (concrete after a few years of frost or metal textured against slipping), markedly textured with dots or bars that can be detected by shoe or cane.

Certain heavy manhole covers may be equipped with one or more hooks that facilitate lifting it. Such hooks may protrude and move independently.

Manhole cover stability

When a person steps on a manhole cover, it may be either sitting still without motion or move perceptibly during a normal walk.

From this aspect, it may be considered stable, a little movable or is swinging a lot. The movement may be accompanied by no sound, a little sound (possibly more audible due to a vehicle) or is considered very noisy (triggered easily by pedestrians) and heard across the street with traffic.

Manhole cover size

Whether a given manhole cover is observable by cane depends on its physical properties. One such measure is its diameter=* (in case of a circular shaped cover) or its width=* and length=* (in case of a rectangular shape).

Adding its extents may help the navigation app announce how easy the cover is to encounter. If it spans a sizable proportion of the sidewalk, it is probable that you will step on it, while if it less than 20cm wide, you would have to actively probe for it.


The cover of a small valve can be mapped with the same set of new and existing tags used for manhole covers (such as its shape, diameter, protrusion, stability).

The valve is usually closed off with a plate that sits in level with the surrounding surface. If it is damaged or missing, either a small hole gets exposed or part of its structure or an axle may be observable. If its locking mechanism is damaged, it can be opened by curious individuals passing by and left partially closed (protruding). This may pose a tripping hazard. The surroundings of such vandalized covers may only be marked by spray paint instead of fencing it off safely until repaired.

Hence, as a form of defensive navigation, apps should announce the position of nearby valves and manhole covers so that one would ideally not step on them directly before probing it by cane.

Holes in a paved surface

Do detectable deep holes interrupt an otherwise even surface? What are their diameter? Are they protruding even a bit or lined by plates or a rim? They may be left after a previous object was removed or due to deterioration.

Concrete slab foundation

A street cabinet, manhole, water tap or fire hydrant may have a concrete base for foundation. This base may either be in level with the surrounding surface or it may protrude by an observable amount, possibly posing a tripping hazard.

Its shape may be either round (circular, oval or stadium) or have corners (square, rectangular).

It may be surrounded by grass, soil or usual walking surfaces such as asphalt, concrete or paving stones.

Front yard gardens

Small plots of gardens can be planted on public property immediately outside the fence delineating the private property next to the sidewalk. It may be maintained by the local authority or the residents. It may cause an observable curvature in the sidewalk or introduce a bay.

The soil in the garden may be in level with the top of the sidewalk or an observable difference in elevation may exist (i.e., at least 1cm). It may have a side made of irregular stones or concrete plates.

Even when it it is not trivial to discover by cane, it is good to know where flowerbeds or thick hedges reside because to protect the flowers, you should not cross the road at that point. It is also better for crossing the road after it rains when soil gets muddy, while grass can be mostly walked through.

As a related concept, a long strip of grass or bare soil may line one or both side of a sidewalk such that there is an observable difference in its height. Such strips of village green are usually not micromapped with polygons to save time, but its properties might be useful to know. A possible simplification in such context would be to add its properties to the line of the sidewalk. Such strips of grass may be useful for walking your dog on a hot sunny day without it burning its paws. Such an idea would be:

Rails on either side of sidewalk

  • handrail, guardrail: is it solid, grated or supported by distant posts (more difficult to notice by cane), which side is it, may help both for stairs, to follow the curvature of the path and in case of dexterity issues
  • low rise metal parking guards: trip hazard
  • chain between posts: either as a parking guard or to keep pedestrians from stepping on the street, but may be of low rise type posing a trip hazard

Guard rails around an object

A street cabinet, bicycle stand, shopping trolley bay, water tap, corrosive potential measurement station or fire hydrant may have guard rails or fence around it.

The type of guard rail or fence around gardens may vary. It can be composed of individual metal bars bent in a U-shape so it hits the ground as if it was two posts. Each individual bar may be either back-to-back, welded together or held together with a metal clip to galvanic ground it, or they may be spaced out at a small distance. The distance may allow your fingers to go through or you may far enough to allow fitting your legs to step through it.

Footway surface

The quality of the surface of a sidewalk or footway or interruptions therein may provide a navigation guide for example to find shops or where one can safely cross the road. It may also be used for navigational decisions when one is using a wheelchair, pushing a baby stroller, wearing roller skates or riding a kick scooter or a skateboard.

The main observable material of a section of footway can already be tagged with surface=*. There exists a less precise alternative for additionally noting whether its surface is patchy or cracked with smoothness=* and track_grade=*. Such deterioration can occur more often near inclined driveways where otherwise heavy vehicles are passing often. Weeds or roots may cause small bumps as large as the palm of your hand to form on pavement which has insufficient foundation.

Most sidewalks molded on site out of long rectangles of concrete or asphalt are periodically delineated by small voids to aid in later modular repairs and thermal expansion. Mapping each of these voids can be excessive work. However, if they occur rarely on the given street, mapping them provide more information. Soil or foundation under some of the slabs may have slightly slipped, causing neighboring slabs to not be in level. One side or both may have a discernible difference in height, posing as a tripping hazard or a nuisance for devices with small wheels.

The kind of temporal irregularity could be mapped in a more structured way. Is the pavement missing in small patches, revealing the underlying concrete foundation or a previous layer of asphalt?

There exist tags for a footway constructed from paving stones to mark the size of each tile. What is still missing is marking the length and surface of the gap between individual tiles. If they touch, what shape are their edges rolled in, are they flush flat (possible to ride a kick scooter on it) or are they rolled?

One-way entrance

entrance=exit implies that it can not be used to enter a given place. We should also be able to map that an entrance=main door can only be used to enter, but not exit (enforced via automatic doors or rotating gates for example).

The drawn corridor and tiny section of outdoor sidewalk may also be tagged as as oneway=yes to signify this. That would require more micromapping and maintenance effort than if we just wanted to note this information at a higher level on the node.

Footway slope

Parts of the surface of a footway and sidewalk may be depressed or elevated by roots of the surrounding vegetation. Poodles of water or mud gather after the rain in such holes. Walking on it may feel like riding a roller coaster.

Elevation caused by roots could be marked up as properties of the tree nearby. As an alternative, each notable bump and depression may be mapped as a new node attached to the highway line similar to how traffic_calming=bump is mapped on roads.

The sidewalk may be intentionally noticeably elevated immediately in front of a few houses. The edge on each transition may not reach the threshold to be considered a single step, yet pose a nuisance to users of small wheel devices. The transition may be more gradually rolled, but this is still detectable as you walk through it.

The incline towards the direction of travel can already be mapped with incline=*. However, another dimension could also be mapped that states whether the footway leans to the right or to the left (possibly even the inclination angle as well).

As a driveway intersects with a sidewalk, one half of the sidewalk may appear sloped in either direction or both: higher towards the right hand side, higher towards the left, higher both sides with a valley in the middle, lower towards the right, lower towards the left, lower both sides with the middle elevated. This is independent of the kind of kerb present on either side.


Its spacing might be horizontally irregular while mappers would prefer to not split one to 20 parts of 1-3 steps each. Construction choices or aging of the steps can result in vertical side plate may slightly protrude above the upper surface of each step or it may have separated a bit horizontally. Navigation apps should avoid such difficult steps and traversing them may require careful effort from even the sighted pedestrian.

To allow pushing up a baby stroller or a bicycle, part of the steps may be overlaid by either a wide flat, but highly inclined ramp made of concrete or metal. It may have two thin flat plates next to each other in axle distance for the same purpose with steps uncovered between them to facilitate pushing the stroller. As an alternative, single thin flat plate or tub may accommodate pushing up bicycles only.

All of these pose a tripping hazard for the visual impaired. It may be useful to know which side of the steps it lies on (left, right or middle) and whether they are marked by visually contrast.


As you want to cross the road, it can prove beneficial to know the approximate size and shape of the kerb=* to know how big you need to step.

Construction choices or aging of the kerb can also result in plate protrusion (i.e., the side bulging out on top instead of showing a round profile).

The kerb may be lower around the corners, while it could be high along the rest of the road. This provides for localization information even lacking tactile marking. You may also prefer to cross the road at these designated spots due to precise alignment and easier to safely walk through.

The side of the sidewalk nearest to the fence may stay at constant height while the side facing the road may have a bay of kerb going in a driveway as a design element. When walking on the sidewalk, this will feel somewhat like a single step both before and after the driveway, but to an inclined plane.

Just a single stone or two might be missing from a kerb. This could be useful as a navigation aid when following the kerb. A simplified solution would be to place a node with kerb=* and height=* on the kerb line. Where the kerb line is not marked separately, the node on the sidewalk line could be prefixed by side, such as left:kerb=* and left:kerb:height=*.

Pedestrian crossing

A designated highway crossing with lowered kerb, but without tactile marking may also pose a hazard. Certain corners may be safer to cross than others either due accessibility, hazard or visibility to motorists. Part of this may be inferred from existing OSM data. For example, a shrub, tree, advertising board or fence may block visibility from certain angles.

Tactile guides

Multiple types of tactile markings can be observed. One kind guides the user around difficult to navigate features (such as away from hitting your head into the underside of steps). A different kind informs about an intersection of paths you can take. Yet another one warns you about a pedestrian crossing where you need to stop before you step on the road. The edge of a public transport platform is also lined with markings.

No existing tagging is present for this, but a handful of examples started to appear for tactile_feature=attention;warning;guidance that may be taken as inspiration after contacting the editor who started using it.

Warning blocks:

  • blister: pedestrian crossings
  • offset blister: off-street platform edge (e.g., heavy railway, subway)
  • lozenge: on-street platform edge (e.g., bus)

Directional blocks:

  • linear guidance: around obstacles, towards terminals, where edge following is not available
  • empty: 90 degrees intersections of linear blocks can be signalled by a non-tactile tile so that you can probe the available options around you by cane
  • corduroy hazard: call for attention attention at top and bottom of steps, foot of a ramp, level crossings, approaching an on-street platform, footway joins a shared space
  • cycle way: at regular intervals and junctions


It can pose a hazard if a ditch lies between the sidewalk and the road.

The depth (and inclination or width) of the ditch and the surface (grass, concrete) of its sides can be tagged. Whether water is usually present. May give home to animals producing sound (crickets, frogs).

Crossing a road

If a sidewalk is not directly attached to the road with a kerb, there may lie a small strip of grass, ground or possibly a small incline separating the two.

Thus, crossing the road may not always be safe or possible at all for one with accessibility issues. A navigation app may suggest crossing the road through a pair of driveways which are approximately facing each other on opposing sides of the street. They may be easier to find when their surface, incline or kerb differs compared to the sidewalk.


The visual impaired may clearly feel whether one side of the street or another or one street or another offers more shade to travel the same distance at the same time of day. They can both map this and utilize this information from the map for great benefit.

A sighted person would simply see the shade and go to the other side of the street or take another turn at the next intersection.

This surely wouldn't be a problem if every sidewalk, fence, road and plant had centimeter-accurate position and width specified, but we clearly can never get to that point, so an approximation is in order. The existing tag shade=* is not well developed yet as per its talk page.

Rain cover

Similar to shade, vegetation or the construction of the roof hanging out on one side of the road may provide more protection than the other and this information could prove useful when one forgot to bring their umbrella.

See also:


Where to not scratch yourself or pick your nose.

Discovering new objects

Objects around sidewalk

If every point and way without exception would be surveyed according to centimeter-accuracy using RTK GPS and drone aerial imagery, such microtagging would be redundant. However, as worldwide coverage of this can not be realistically anticipated, navigation tools could utilize this information in a form that is much easier to survey and maintain on the long run.

It would be a viable simplification where no sidewalks are drawn separately, and the road is tagged with sidewalk=* instead. One such tag would be to indicate the relative position of each given item of interest for the purpose of avoiding danger or as a navigation aid.

Such objects are: street lamps, fire hydrants, street cabinets, parking meters, traffic signs, trunks of trees, thunks, waste baskets, corrosive potential measurement stations. It is mostly of interest if they are within the enclosed volume of the footway plus the reach of a cane (let's assume up to 50cm from the sides for now).

The position can be relative to the walking trajectory on a sidewalk or in relation to other objects such as a building, fence or the road. It is useful to know where each such object occurs to help maintain alignment towards an imaginary safe trajectory or to decide which way to sidestep the given object. The position of such an object may be:

  • on the side of the road: may be used as a crossing aid
  • just outside the road towards the side of the sidewalk: may be used as a crossing aid, may still find it if walking on the side of the road
  • outside reach from sidewalk (deep within the village green): may be used as a crossing aid
  • just outside the sidewalk on the side of the road: shouldn't pose a problem to avoid it, but may find it if you are following the kerb of the sidewalk
  • on the side of the sidewalk nearest to the road: should be avoided from the right if walking on the right side
  • in the middle of the sidewalk: may be avoided on either side
  • on the side on the sidewalk furthest from the road (i.e., towards the buildings or fence): should be avoided from the left if walking on the right side
  • near the fence or a building (either mounted on it or just installed in front of it or within a small strip of village green next to it): shouldn't pose a problem to avoid it, but may find it if you are following the wall

Public transport platform next to sidewalk

If you walk along the length of a sidewalk, it is beneficial to know which side you can go around a bus stop and the probable group of waiting passengers. Can you walk past behind it, in front of it or through it? We could mark whether the bench inside the bus stop rests with legs on the ground (i.e., can be easily probed) or if it is a floating plate attached to the backside.

If a shelter is missing walls on some of its sides, one may inadvertently walk through the shelter on either or both sides, possibly bumping a knee into a floating bench. A shelter may have either 0, 1 or 2 sides in addition to its back plate and top.

As you are sitting in a bus stop, do you need to be cautious about crossing pedestrian or cyclist traffic? (Such cases actually exist in Europe)

Tagging this might be done either by how objects are marked as installed on the right/left of the sidewalk, or an elaborate interconnection of path lines may be introduced.

Objects projected to the same surface position

Multiple objects may be attached directly onto each other in real life, such as an advertising billboard on a street lamp which is also holding power lines, an audible power line transformer with possibly antennas on top. As the logical support on the ground or the 2D projection would result in the same GPS coordinate, designated options must be considered for representation in OSM, as mentioned in the.

fixme OSM wiki page

Let's focus on this problem with regards to the needs of the visual impaired. The workaround of placing the objects at slightly different coordinates without further marking may result in broken expectations when a future navigation tool shows or reads aloud the sequence of objects encountered as if they were separated.

Although, relations are more difficult to work with, they may provide for a geometrically accurate representation. Visualization will still suffer, though. If the POI nodes at the same position were plainly added separately, a new tag may state whether a given one is anchored to another.

Inaccurate anchoring

A simple workaround for both the case of overlaid points and in general would be to mark all nodes participating in such perturbation as being inaccurate. While mathematically speaking, it would be valid to add accuracy=10, it would not be sufficient, as that may also be interpreted as a possibly uniform offset from aerial imagery. Due to this, many data users and humans usually assume a relatively static local neighborhood of each object.

Instead, we may need to introduce a new tag to disambiguate between the kind of inaccuracy of a given object: whether nearby objects are aligned to each other (i.e., the relative distance between them is accurate) or if they were perhaps added by separate contributors or from vague memory recall.

To aid contributors improving the map precisely, we may introduce yet another tag to indicate whether the submitted geometry of the given object was anchored to some other existing object, such as drawing them together or adding a new object from photos, memory and a rough estimate based on the coordinate of an already added object nearby. For example, a waste basket may have been been added on the right side of an already added fire hydrant.

Road marking

Smell and stickiness of wet paint on pedestrian crossing and other road markings (give way, new lanes).

Feeling of walking on sanded surface over paving stones on traffic calming, sidewalks and crossing.

The app may ask for the surface and smoothness of sidewalks and paths, especially if it is ambiguous when laid through green areas. Asking for properties about the road itself can be dangerous, unless the route crosses the road.

Traffic calming

Feeling traffic calming devices either by cane, walking through them or as you hear vehicles bumping into them.

The single aim of a traffic calming device may be to calm ongoing vehicle traffic on the road. It may also be deployed multi-purpose to also facilitate crossing the road by pedestrians. In the latter case, it may be visually distinctive, its surface is usually flat, kerbs on either side may be lowered and village green may be interrupted by a path.

A kind of traffic calming bump exists which is composed of many small dots or strips to facilitate crossing by single tracked vehicles such as bicycles.

Is it traffic calming if there is a step in the road (i.e., they have elevated a whole section of living street)?


Fragrant blossom of trees, augmented by knowledge of the relative timing by species.

The strength of the odor is dependent on the species and may be sensed either when standing next to it or even across the street (e.g., lilac, wisteria)

Smell or taste of fallen, ripe fruit.

Touch of surface and shape of leaves, bark, inflorescence. The placement of a plant may be:

  • fully residing on public property
  • mostly accessible (the trunk or major portion accessible)
  • a useful proportion sticking out, accessible to touch
  • a non-negligible part posing a hazard to passer-by
  • directly next to the fence inside, does not stick out, but fragrant
  • inside, but close by and clearly visible from outside



  • blossom
  • fruit by kind


  • sewage: a man hole or ventilation pipe
  • stale water: not quite as bad as raw sewage, but maybe a contaminated ditch or other places where water is not flowing and aerated properly
  • dog excrement: a dog waste bin
  • communal waste: either a waste basket or a recycling container
  • wood chips: a lumber mill, furniture maker or store
  • honey
  • bakery: it might be reasonable to mark whether a shop bakes something in place and if it can be smelled from across the street or even further


  • insulation: slightly burnt, heated plastic insulation from a trasformer or an electric motor
  • glue
  • solvents
  • plastic
  • chlorine: maybe a swimming pool
  • cosmetics: such as perfumes used by a hairdresser
  • strong antiseptic cleaning products: such as near medical professionals
  • gas odorizer: a fuel station, gas distribution substation or a leak to report
  • liquid fuel: perhaps a fuel station
  • engine oil: perhaps a vehicle repair shop
  • rubber: perhaps a tire shop

Interview notes

a járda az útpadkán fut-e, azaz összetalálkozik-e a botom a szembejövő autók oldalával ha a járdaszegélyt kopogtatom, avagy van valami elválasztás (ha nincs elválasztás és még küszöb sem ráadásul gyakran ráállnak a kocsik)

amennyiben a telkek felől kopogtatom a járdán, hasznos tudni ha valahol nagyobb beugrások vannak kocsibejáróknál, nehogy saroknak higgyem és beforduljak

a járda szélességét nagyságrendben praktikus tudni, illetve ha azon jelentős beugrás van (plusz mi miatt)

falkovetes vagy parkolo auto kikerulese okan: a jarda bal/jobb oldalan mi van: kerites, melyedes (benne esetleg gaz), fal, kerb, uttest, bokor, fu, fold, neha atlepheto vegyes zold, kavics

Bár érdemes falkövetéssel bevenni a sarkokat, gyakran át kell kelni az úttesten sajnos. Néha meglepő mankóhoz fordulhatunk ha nagyon ingerszegény egy adott hosszú járda: ott lesz a T-sarok ahol átkelhetek ahol a járda közepén található tűzcsap 1 méterre van egy utcaszekrénytől.

Most láttam élőben további használati esetet street cabinetre: nem csak ülni lehet a tetején ha elég alacsony, de ha elég magas és lapos a teteje (roof:shape=flat), akkor még asztalnak is jó, iszogatni, kártyázni, sakkozni, csomagolni, stb.

hangos vagy tapintható iránytű

ha végig szintben van a járda mentén a padka, jobban ráparkolnak az autók

TTS jól felolvasni ha 1-2 méterenként van 1-1 lépcsőfok

StreetComplete or Every Door are not suitable for blind people


User:Mahdi1234/Milos 01

Collaboration with the visual impaired



Navigation anchors

  • Obstacles
  • Tactile markings
  • Danger
  • Objects that have various uses in real life for others but have a unique shape, texture or material
  • (see OSM wiki for further types and details)

Real-time contribution

  • Reporting navigation errors to review later
  • Found features that are not mapped
  • Mapped features not present on the ground
  • Request for navigation anchors
  • Answer questions in fixme keys, map notes and QA tool suggestions

Distant contribution

  • Review density of navigation anchors along a path and request more in sparse areas

Software development feedback

  • problem: most developers and map editors are sighted

Mapping feedback

  • proposal for new types of entities to map
  • refine properties of existing entities
  • workflow changes
  • Problem: participants and conversations on existing OSM internal communication channels are very technically inclined, not suitable for general consumption


Guides for mobility impairments


Most of these should be updated under the scope of this project.

Existing tags for visual impairments documented on the wiki






Existing undocumented tags for visual impairments found on taginfo