Clarify in-town vs out-of-town speed limits

[smichel17]

When a road has no speed limit sign, you are asked to choose whether it is in-town and out-of-town.

I grew up in a fairly rural area where there are clear distinctions between town center and out of town roads. Currently, though, I'm mapping in a fairly dense, suburban, residential area (Queens, NY). It's not clear to me whether these streets should be marked as in-town or out.

Is it possible to display any additional information that might help me make a decision? Either explicitly clarifying about suburbs in the question, or providing context so I can understand the effect of each choice (What's the in/out of town speed limit? If 20/35, this is probably out of town. If 25/45, probably in town).

[westnordost]

Hmm, not really. Usually, I guess also in the United States, the default speed limits (when no signs are posted) differ between in-town and out-of-town. The situation in Germany is, that it is clearly signposted when a locality begins and when it ends (because of the default speed limits).
Is it different in the US?

[matkoniecz]

https://en.wikipedia.org/wiki/Speed_limits_in_the_United_States#Speed_limits

If I read it correctly then "Residential" ten to have its own speed limits, though it is unclear how it is defined.

According to https://en.wikipedia.org/wiki/Speed_limits_in_the_United_States_by_jurisdiction

• Alabama has separate limits for urban areas, unpaved roads, rural paved county roads, other two-lane roads, four-lane roads, Interstate Highways
• Alaska has three classes of urban areas - business district, residential district, alleys and single default limit for all other roads
• Arizona has urban areas and school areas and as bonus has night speed limits in some places
• etc etc

And according to http://www.mit.edu/%7Ejfc/urban-speed.html local goverments in some states may set their own limits (it is unclear is it equivalent of European zone sign or is it allowing to pass legislation affecting speed limits without signing them)

A Y'' in the Area?'' column means state law allows local governments to set speed limits effective in an area, as opposed to posting speed limits on every street.

[smichel17]

Hmm, not really. Usually, I guess also in the United States, the default speed limits (when no signs are posted) differ between in-town and out-of-town. The situation in Germany is, that it is clearly signposted when a locality begins and when it ends (because of the default speed limits).
Is it different in the US?

In Massachusetts, in town is 25 mph and rural roads are 35 mph. Residential roads are also 25, but there's no clear line that I know of between residential and rural, since people live in the latter as well; it's mostly a "feel" thing. (Note: this is from personal experience; there may actually be a formal set of rules I don't know about. But, I wouldn't expect the average mapper to know what they are).

Although that's vague, it actually does end up working in practice. Based on the width of the roads and population density, I generally know how quickly I am expected to drive on any given road.

The lack of clarity is a problem when mapping, though. Particularly: while I can often estimate how fast I should drive, it's not clear to me what the effect of choosing "in town" vs "out of town" is, so I can't apply my intuition about the speed limit.

How is this recorded in the OSM database / is there a standardized format? Depending on those answers, I could see one or both of these solutions:

• Instead of selecting "in town" vs "out of town", allow putting an estimate of the speed limit.
• Separate into two quests, one for marking no sign and another for providing additional info (since "No sign" is still useful info even if it's not known whether the road is in or out of town).

[matkoniecz]

it's mostly a "feel" thing

https://en.wikipedia.org/wiki/Speed_limits_in_the_United_States_by_jurisdiction#Massachusetts has

30 mph (48 km/h) on a road in a "thickly settled" or business district for at least 1⁄8 mile (200 m)
40 mph (64 km/h) on a road outside of a "thickly settled" or business district for at least 1⁄4 mile (400 m)
50 mph (80 km/h) on a divided highway outside of a "thickly settled" or business district for at least 1⁄4 mile (400 m

with citation link to https://malegislature.gov/Laws/GeneralLaws/PartI/TitleXIV/Chapter90/Section17

[smichel17]

Alright, since my estimate was wrong (although close), maybe let's not allow an estimate :P
Or allow it but make it a note instead of a formal field.

[westnordost]

I already created a special case for the United Kingdom regarding implicit speed limits. There, it does not matter for which implicit speed limit apply whether a road is in or out of town, but another factor - namely whether it is a single or dual carriageway. See code.

What I want to say with this is that it is possible to add more exceptions, even on a per-state level in the US. But if something should be implemented there, I would need to know, what the surveyor should be asked in the case he specifies that there is no speed limit posted.

Edit: But from your description, I guess, the "in town" vs "out of town" question would still be the correct question to ask.

[matkoniecz]

The problem is that it is unreasonable to ask user whatever road matches unspecific 'thickly settled" or business district for at least 1⁄4 mile'

Is there a good way to tag that maxspeed is unsigned, without tagging max speed?

[westnordost]

How is this recorded in the OSM database / is there a standardized format? Depending on those answers, I could see one or both of these solutions:

It is recorded as not setting maxspeed to any numerical value but instead set maxspeed:type to US:urban or US:rural (in the US).
Data consumers (routers, etc.) are then left to figure out the probable speed limit on that section, given that information. This might be very straightforward for certain countries and might be somewhat fuzzy for others (like the US, I guess).

[westnordost]

The problem is that it is unreasonable to ask user whatever road matches insane 'thickly settled" or business district for at least 1⁄4 mile'

Well, as @smichel17 said, it's a "feel" thing. So, while the 1⁄4 mile might be the hard definition, in practice, people will decide whether something is urban (aka "thickly settled") or rural (aka "not thickly settled") subjectively. As subjectively as a surveyor with StreetComplete would decide that. (Also, by the way, the definition you cited is really not that fixed because "thickly settled" is subjective anyway.)
So I think, actually, we are fine here. "Is this in town or out of town?" is the right question to ask. But let's ask @smichel17 about the wording.

Is there a good way to tag that maxspeed is unsigned, without tagging max speed?

No

[smichel17]

I think I figured out the root problem I was having answering this question for a suburban area like this. If you asked me "Is it Urban or Rural?" I'd end up saying "Urban". If you asked me, "Is it in town or out?" I'd say out.

I think in this case, US:Urban makes more sense as a label (40 mph is not reasonable on these roads; 30 is). So, maybe a solution would be to just make the choices Urban/Rural instead of in/out of town?

[westnordost]

So how would you rephrase the text in the dialog? Would "built-up area" also be good or even better?

[smichel17]

Maybe something like, "Roads have a different default speed limit in urban (in town or densely populated) and rural (out of town, sparsely populated) areas."

I think the italicized part could be left out and would still be implied. That would make the sentence flow better, so I would do it unless you're concerned that it would be confusing.

[westnordost]

The current text is:

Where is this street?
Urban roads have a different default speed limit than rural roads.
[In town] [Out of town]

So the description already mentions urban and rural. It were the button names I guess that confused you.

[smichel17]

The description already mentions urban and rural.

I know; I based my suggestion on the current text.

It were the button names I guess that confused you.

Specifically, it was the fact that the button names conflicted with the description text. Changing the labels and (more importantly) adding the parenthetical clarifies that I should pick the Urban label if the area is densely populated, even if it is out of town.

[rugk]

I also think in the German version this is less problematic, as there "in town" and "out of town" are the official terms for these things ("innerorts", "außerorts") that everyone knows.
So maybe the literal translation into English has caused some confusion here.

[westnordost]

Ok, I will change it as suggested and also change the button names (in English) to rural and urban