The Thai wiki guidelines for service=alleyalign 100% with the global wiki, without deviation. You can review it here.
A review of the global service=alley wiki changes since 2010 reveals no mention permitting the general use of the service=alley tag for narrow roads.
In 2013, an exception was introduced for medieval European settlements, focusing on “very narrow streets running between buildings, providing public through-access.” This scenario is specific and irrelevant to urban and rural settlements in Thailand. Further details are available here.
Routers recognize lanes=1, and using highway=residential + lanes=1 has been acknowledged as a valid approach for routing. Additional information can be found here.
We can certainly reconsider borderline cases and examine mapping practices for adopting a different tagging approach for roads narrower than, for instance, 3 meters.
However, for the typical residential roads with a width of 3 meters or more, as you described above and approved below in Facebook a few days ago, I doubt you will find many “supporters.”
Ok, I hate answer that says “because I say so” or “I know an alley when I see one”. I find it utterly useless in a discussion. But that said, this answer added a lot of constructive feedback that I think is important.
I think we can all agree with Russ on the fact that we don’t want to route cars through tiny residential roads that they can barely fit through. But this might lead to an overuse of alleys where I believe most of us don’t see an alley.
We do need to solve the routing problem, but maybe there is a better way than tagging everything as alleys for the router. It might be worth looking into which tags the routers are actually using and seeing if anything applies better than an alley, or working with the routing developers on tags we think they should consider as well.
I don’t have the solution, but I just wanted to say I appreciated the last comment from Russ which highlighted an actual problem.
I agree with Johnny. I see the issue here is how we can get the router to do the right thing. Also, we should be aware that tagging for routers may be comparable to tagging for renderers, though it is not the same and is not totally wrong. Perhaps we need to do more investigation on the router side before making any changes in the mapper side. So, service=alley is not a problem, but rather one possible solution, and I’m not completely against using it. However, there might be another option.
As far as I remember, the OSRM default car profile won’t route a car down a road with less than 2m width, and it will apply a penalty for any way less than 3m in width, and for any way with lanes=1 that is not oneway=yes. The penalty assumes you can only drive at half the usual speed, which is effectively the same as saying a similar but wider road is preferred if it’s less than twice as long.
Impressive recall! I’ve begun documenting tag support for widely used open-source routers; you can find the information here: Routing/Narrow Roads - OpenStreetMap Wiki
Update: I have gathered feedback from regular members of the global community, available at the following link:
Here are the key findings:
roughly half of the participants support the tagging approach of highway=residential along with either width=* or lanes=1.
the other half of the participants favor highway=service + service=alley.
While there isn’t a decisive majority for the highway=residential option, proponents of service=alley have presented valid arguments, citing cultural differences that make it challenging to achieve a global consensus on the matter:
Naming conventions: “Alleys” is a commonly used term for narrow residential roads in Europe and other countries.
Front/rear access concept: The concept of front/rear access in housing estates is prevalent in Western countries, as seen in the Radburn design housing concept.
Medieval cities: Narrow roads are common in European old cities and settlements.
Lack of Routing support: Only OSMR considers width and lanes for routing (see Routing/Narrow Roads).
Lack of Rendering support: Most renderers do not consider width or lanes.
Additional research and discussions by @Kovoschiz can be found in the wiki, especially regarding the uncommon use of the tag in Asia or its non-recommendation in Taiwan (Talk:Tag:service=alley).
In conclusion, like many other countries, the Thailand community members will need to vote on a Thailand-specific rule for narrow roads.
Given the absence of a front/rear housing access concept in Thailand, the fact that a “Soi” is “a side street branching off a major street” and the impracticality of “tagging for the renderer,” the only relevant argument in Thailand would be the lack of Routing support.
Also, very narrow roads in Thailand resemble those found in European medieval settlements, which is already an official global wiki use-case.
Once more feedback is consolidated, including input from Grab’s Navigation team, we will propose several options with clear specifics, pros, and cons for community voting.
@julcnx Today it is not true that 2/3 of the participants support the tagging approach of highway=residential along with either width=* or lanes=1. The voting is currently 55%- 45% and just yesterday it was 52%-48%. Please give it more time to stabilize.
The “correct way to tag roads located inside a gated residential community” is mostly uncontroversial and well established as far as I know. Map them as highway=residential if they look like most residential streets, or highway=service if they are mainly accesses to parking lots or for supply or for passenger pick-up and drop-off. In both cases, also add access=private.
For true living streets, where pedestrians have legal right over vehicles at any point along the way (not to be confused with drivers’ legal duty to drive carefully near pedestrians), they can be mapped as highway=living_street where they look like residential streets and as living_street=yes in combination with highway=service where they do not. Gated communities often set their own rules and may signpost or internally rule that pedestrians have the greatest right to use some space on its ways, but as this is often difficult to verify because it is rarely possible for surveyors to enter such communities, it is unusual to see highway=living_street mapped there. But whenever confirmed, it is possible and recommended to map them as a living streets.
Since August 2013, the wiki page for highway=service mentions as an example that service=alley may be used for a “narrow road, alley or path between properties”. In January 2010, this phrase was even less rigid: “a road between properties”.
To name a few, there are more than 17 thousand alleys mapped in Tokyo (verifiable with this query), more than 14 thousand in Ho Chi Minh City, almost 7 thousand in Taipei, more than 3 thousand in Metro Manila, and more than 1400 in Beijing. A bit of random sampling allows one to conclude that most of them correspond to narrow public residential streets.
I have updated the results. The point remain that there will be no landslide majority nor a global consensus reached globally due to cultural differences, and historical disagreements.
The feedback we received globally was valuable, and we have enough information for our Thailand community to decide how to go forward. I have done my best to summarize my findings, but other members will surely do their own research.
Your input was helpful in the process and like others will be taken into account, but please… leave some space for other Thailand community members to communicate in this thread.
I get you are passionate about using service=alley for narrow roads in Brazil and globally, but believe me, flooding multiple replies in every wiki discussions and forum threads as you do won’t help your cause, it might just do the opposite. Take a break, and thanks for your understanding!
The “mailing list” Etiquette your refer to also says ”If you’ve made your point already, you don’t need to tell us all again"
You’re a strong supporter of service=alley for narrow residential roads, and I respect your take. Maybe we’ll consider something similar to what’s done in Brazil. But, let’s hear from the Thailand community on this topic. Thanks for making your point loud and clear!
This is only valid within the same thread. It cannot be assumed that readers of this thread have also read all the other threads, such as the one about service=alley. So, this is inevitable as the two topics overlap.
I am still in favor of only using highway=residential for public front access residential roads. By the way, given how widely used service=alley is over the world, I wouldn’t be opposed to using it if we could establish some solid criteria for them. I’ll add some ideas here.
First, service=alley is a sub-tag, thus it is optional. It is not wrong to tag the way just with highway=service; hence, we should only use service=alley for roads that are appropriate to highway=service.
A highway=service is typically not used for a through traffic road. In other words, people rarely use that road unless it is absolutely necessary.
As a result, a service=alley should be used with caution on highly limited roads, such as very narrow roads. We can position it between highway=path and highway=residential based on width. The particular number of width should be determined.
Here’s the input from Grab, who leans towards the highway=residential + lanes=1 approach but is willing to adopt a different schema if there’s a community consensus, similar to a few other countries:
I personally delved deeper into the OSM usage of service=alley in Northern Thailand, and I couldn’t formulate a concrete proposal.
If we consider roads where bi-directional traffic is possible only at certain spots (width less than 4 meters), this rule would apply to literally millions of roads.
Conversely, if we consider roads where bi-directional traffic is strictly impossible (no gaps or presence of walls/fence/buildings/sidewalk), we could find a much lower number.
However, there is no standard road width in Thailand; it can have any measurements. This is open to interpretation, and examining usage samples below reveals that service=alley has been applied indiscriminately for various widths (some are 4/5 meters wide) or even for different uses (private driveways).
I routinely modify motorcycle paths (narrower than 2 meters), and distinguishing them is challenging, especially without a visible car parked in the driveway.
Apart from the reasons mentioned earlier, I personally believe that introducing another highway tag based solely on road width not only complicates matters but also increases the likelihood of further editing conflicts.
I have reached out a week ago to regular Thailand community members whether they have a concrete proposal for service=alley taking into these points below but I have still not received any answers.
Should we make exceptions for narrow residential roads within a certain width (like 3 or 4 meters)?
How do we ensure that estimating the width doesn’t lead to conflicting opinions?
Should we base the classification on the presence of “in-between buildings” or walls/sidewalks?
Does the classification apply to one-way streets, or only those allowing bi-directional traffic?
Historically, most Thailand community members have expressed a preference for labeling narrow roads with highway=residential, and this is currently reflected in the wiki.
To transition to service=alley for narrow residential roads on the Thailand wiki, we would need a clear, non-conflicting proposal for service=alley, followed by a vote with a substantial majority.
