Re: [Talk-us] Prima Facie Speed Limits
Am Montag, 8. September 2014 schrieb Tod Fitch : How does this sound? +1 Cheers, Martin -- Martin Koppenhoefer (Dipl-Ing. Arch.) Via del Santuario Regina degli Apostoli, 18 00145 Roma |I|I|I|I|I|I|I|I| Italia N41.851, E12.4824 tel1: +39 06.916508070 tel2: +49 30 868708638 mobil: +39 392 3114712 mobil: +49 1577 7793740 m...@koppenhoefer.com http://www.koppenhoefer.com Hinweis: Diese Nachricht wurde manuell erstellt. Wir bemühen uns um fehlerfreie Korrespondenz, dennoch kann es in Ausnahmefällen vorkommen, dass bei der manuellen Übertragung von Informationen in elektronische Medien die übertragenen Informationen Fehler aufweisen. Wir bitten Sie, dies zu entschuldigen. Any views or opinions are solely those of the author and do not necessarily represent those of koppenhoefer.com unless specifically stated. This email and any files attached are confidential and intended solely for the use of the individual or entity to which they are addressed. If you have received this email in error, please notify postmas...@koppenhoefer.com Please note that to ensure regulatory compliance and for the protection of our clients and business, we may monitor and read messages sent to and from our systems. Thank You. ___ Talk-us mailing list Talk-us@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-us
Re: [Talk-us] Prima Facie Speed Limits
On 09/08/2014 05:27 PM, Tod Fitch wrote: [...] instead there is a state wide prima facie limit: source:maxspeed=US:CA:residential [...] My state doesn't have such a limit, but my city does. Supposing I started tagging things with source:maxspeed=US:VT:Burlington, would anyone be upset that Burlington and residential are in the same place in the hierarchy? (I'm hoping the answer here is no one cares, the value isn't intended to be machine parsable, and both values are understandable by humans.) --Andrew ___ Talk-us mailing list Talk-us@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-us
Re: [Talk-us] Prima Facie Speed Limits
In Europe (at least Germany, Belgium, The Netherlands, UK) people started to add both source:maxspeed=country code:classification and explicit maxspeed tags. Then there is no need for an external DB to lookup the speeds. Although it means that when the speed changes, all roads have to be retagged. regards On Tue, Sep 9, 2014 at 1:00 AM, Tod Fitch t...@fitchdesign.com wrote: California has a 25 MPH rule for school zones while Arizona has (or at least had when I lived there) a 15 MPH school zone limit. It seems that 25 MPH in a residential area is pretty standard but I think states have enough discretion in setting limits that they could vary from one state to the next. So I think the source attribution should allow for differences between states for the same class of road. Thus my suggestion for source:maxspeed=US:CA:residential for tagging in my area. On Sep 8, 2014, at 2:55 PM, Greg Morgan wrote: On Mon, Sep 8, 2014 at 2:27 PM, Tod Fitch t...@fitchdesign.com wrote: Thus far I've only applied the maxspeed tag to roads with a posted speed limit. But here in California most residential roads are not posted, instead there is a state wide prima facie limit: http://www.dmv.ca.gov/pubs/vctop/d11/vc22352.htm I wonder if 15 mph in a school zone and 25 mph in a residential area are some sort of federal standard? The source tag might be useful but not much different than other states. Regards, Greg ___ Talk-us mailing list Talk-us@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-us ___ Talk-us mailing list Talk-us@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-us
Re: [Talk-us] Prima Facie Speed Limits
On Sep 9, 2014, at 6:10 AM, Andrew Guertin wrote: On 09/08/2014 05:27 PM, Tod Fitch wrote: [...] instead there is a state wide prima facie limit: source:maxspeed=US:CA:residential [...] My state doesn't have such a limit, but my city does. Supposing I started tagging things with source:maxspeed=US:VT:Burlington, would anyone be upset that Burlington and residential are in the same place in the hierarchy? (I'm hoping the answer here is no one cares, the value isn't intended to be machine parsable, and both values are understandable by humans.) I think there are two reasons for the source:maxspeed tag: 1) So the next mapper who touches the maxspeed value knows where it came from. 2) To be able to find all the occurrences of maxspeed that were determined by the source. Something searchable but not necessarily machine parseable should be okay. On Sep 8, 2014, at 10:30 PM, Marc Gemis wrote: In Europe (at least Germany, Belgium, The Netherlands, UK) people started to add both source:maxspeed=country code:classification and explicit maxspeed tags. Then there is no need for an external DB to lookup the speeds. Although it means that when the speed changes, all roads have to be retagged. As long as the source:maxspeed value is unique to the jurisdiction then it is easy to find all the roads that need to be retagged. On Sep 8, 2014, at 3:58 PM, Richard Welty wrote: the default speed limit in NYS for unposted roads is 55mph, irrespective of surface type. other states vary; there's a page in the OSM wiki about it. If I recall correctly, NYS changed their rural highways from 50 MPH to 55 MPH when the nationwide 55 MPH limit came into effect in the early 1970s. So these speeds can definitely change, though usually change is slow. I think that if the value for the source:maxspeed tag uniquely specifies the jurisdiction and is something that is readily understandable by a human then is should be okay. So US:CA:residential and US:VT:Burlington or US:VT:Burlington:residential would meet those requirements. Sounds like the responders to this thread are either unopposed or generally in favor of the concept. I think I'll start tagging this way in my local area. Thanks! Tod ___ Talk-us mailing list Talk-us@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-us
Re: [Talk-us] Prima Facie Speed Limits
I'm of the opinion that wherever the speed limit is just the default for that road class, it should not need to be posted at all. Any data user can then infer limits. Martijn On Mon, Sep 8, 2014 at 3:27 PM, Tod Fitch t...@fitchdesign.com wrote: Thus far I've only applied the maxspeed tag to roads with a posted speed limit. But here in California most residential roads are not posted, instead there is a state wide prima facie limit: http://www.dmv.ca.gov/pubs/vctop/d11/vc22352.htm I am considering tagging the unsigned speed limit on residential roads in my area and am thinking of tagging the authority of the speed with source:maxspeed=US:CA:residential based on an extension of the type of things I see at http://wiki.openstreetmap.org/wiki/Key:source:maxspeed How does this sound? Objections? Is there a better way? Thanks! Tod ___ Talk-us mailing list Talk-us@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-us ___ Talk-us mailing list Talk-us@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-us
Re: [Talk-us] Prima Facie Speed Limits
One street here in Nashville, TN, went for several years without any speed limit signs along its three-mile length. Then, one day, it suddenly had signs every half-mile or so. I suspect that someone probably argued their way out of a speeding ticket on the grounds that there weren't any posted limits. Tennessee doesn't have any default speed limits that I am aware of, although one can always be cited for reckless driving. On September 9, 2014 10:47:24 AM CDT, Martijn van Exel m...@rtijn.org wrote: I'm of the opinion that wherever the speed limit is just the default for that road class, it should not need to be posted at all. Any data user can then infer limits. Martijn On Mon, Sep 8, 2014 at 3:27 PM, Tod Fitch t...@fitchdesign.com wrote: Thus far I've only applied the maxspeed tag to roads with a posted speed limit. But here in California most residential roads are not posted, instead there is a state wide prima facie limit: http://www.dmv.ca.gov/pubs/vctop/d11/vc22352.htm I am considering tagging the unsigned speed limit on residential roads in my area and am thinking of tagging the authority of the speed with source:maxspeed=US:CA:residential based on an extension of the type of things I see at http://wiki.openstreetmap.org/wiki/Key:source:maxspeed How does this sound? Objections? Is there a better way? Thanks! Tod ___ Talk-us mailing list Talk-us@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-us ___ Talk-us mailing list Talk-us@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-us -- John F. Eldredge -- j...@jfeldredge.com Darkness cannot drive out darkness; only light can do that. Hate cannot drive out hate; only love can do that. Dr. Martin Luther King, Jr.___ Talk-us mailing list Talk-us@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-us
Re: [Talk-us] Prima Facie Speed Limits
I wonder if 15 mph in a school zone and 25 mph in a residential area are some sort of federal standard? The source tag might be useful but not much different than other states. The federal government doesn't have anything to say about speed limits (in states), as the US Constitution leaves such things to the states. An exception is on federal land, such as national parks or BLM land, where specific parts of the US Code regarding speed limits DO apply. This is why you can get a speeding or parking ticket at Yosemite, but you won't deal with California to fight it or pay the fine: Yosemite is not part of California. Surrounded by it, yes. Part of it, no. My GPS (a still-tough Garmin 60 CSx) does an excellent job of calculating Estimated Time of Arrival (ETA) when routing. It does so by assuming speed limits for all road segments in the current route and guesses I'll travel at those speeds. This is done without assigning a speed limit to each and every road segment, instead implementing a simple table lookup (freeway: assume 65 MPH, residential: assume 25 MPH...). This is a highly efficient solution that keeps the data light and the calculation short and simple, so it quickly produces an accurate ETA result. Though I don't find incorrect (or offensive) the suggestion of tagging prima facie limits with the tagging syntax specified, I find speed limit tagging to be most useful where there are posted signs with a specific number. That's just me, though. SteveA California___ Talk-us mailing list Talk-us@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-us
Re: [Talk-us] Prima Facie Speed Limits
On Sep 9, 2014, at 10:31 AM, stevea wrote: I wonder if 15 mph in a school zone and 25 mph in a residential area are some sort of federal standard? The source tag might be useful but not much different than other states. The federal government doesn't have anything to say about speed limits (in states), as the US Constitution leaves such things to the states. An exception is on federal land, such as national parks or BLM land, where specific parts of the US Code regarding speed limits DO apply. This is why you can get a speeding or parking ticket at Yosemite, but you won't deal with California to fight it or pay the fine: Yosemite is not part of California. Surrounded by it, yes. Part of it, no. My GPS (a still-tough Garmin 60 CSx) does an excellent job of calculating Estimated Time of Arrival (ETA) when routing. It does so by assuming speed limits for all road segments in the current route and guesses I'll travel at those speeds. This is done without assigning a speed limit to each and every road segment, instead implementing a simple table lookup (freeway: assume 65 MPH, residential: assume 25 MPH...). This is a highly efficient solution that keeps the data light and the calculation short and simple, so it quickly produces an accurate ETA result. Though I don't find incorrect (or offensive) the suggestion of tagging prima facie limits with the tagging syntax specified, I find speed limit tagging to be most useful where there are posted signs with a specific number. That's just me, though. SteveA California The DVD map based nav system in my 10 year old car makes the same assumption about speeds based on its three classes of roads. It had wildly incorrect times until I configured it for California speeds. Now it does a reasonable job at estimating travel times on its selected route if I am in California. But typical rural speed freeway speeds vary considerably from state to state and for longer trips the times are still quite a bit off. Assumed values are not as good as actual values. (And my car nav system always tries for the slow way to the southern SF bay are apparently ignoring that CA 152 exists until I actually make the turn on to it from I-5 when it realizes that my way is both shorter and faster than the route it picked, so it has other problems.) A while back I suggested that prima facie speed limits tags be put the boundary area/relation for administrative areas. So the relation for California could specify something like prima_facie:maxspeed:motorway=65 MPH. This would be a simple to implement scheme with relatively few entries in OSM and be easy to update in the rare situation where the law changes. It could also allow for city or county rules to be specified. Routing algorithms could discover the appropriate assumed speeds for any class of road in an area buy looking at the enclosing administrative boundaries and the tags on those boundaries. But that suggestion was met with a pretty cold response by the tagging mail list. Instead a multitude of roads in Europe and elsewhere are being tagged with the prima facie speeds and having a source:maxspeed tag to explain it. My suggestion in this thread will contributed to that so I admit it is not my first choice. Tod ___ Talk-us mailing list Talk-us@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-us
Re: [Talk-us] Prima Facie Speed Limits
There's a functional difference between speed limits and the actual speed driven. For ETA prediction, speed limit data is not all that useful - detailed historical and live speed profiles are. That is not data that is in OSM (or should be). The speed limits are mostly useful for alerting drivers they may be driving too fast. For a system like that to be feasible you will need comprehensive posted speed limit coverage, which OSM currently does not have. Martijn On Tue, Sep 9, 2014 at 12:38 PM, Tod Fitch t...@fitchdesign.com wrote: On Sep 9, 2014, at 10:31 AM, stevea wrote: I wonder if 15 mph in a school zone and 25 mph in a residential area are some sort of federal standard? The source tag might be useful but not much different than other states. The federal government doesn't have anything to say about speed limits (in states), as the US Constitution leaves such things to the states. An exception is on federal land, such as national parks or BLM land, where specific parts of the US Code regarding speed limits DO apply. This is why you can get a speeding or parking ticket at Yosemite, but you won't deal with California to fight it or pay the fine: Yosemite is not part of California. Surrounded by it, yes. Part of it, no. My GPS (a still-tough Garmin 60 CSx) does an excellent job of calculating Estimated Time of Arrival (ETA) when routing. It does so by assuming speed limits for all road segments in the current route and guesses I'll travel at those speeds. This is done without assigning a speed limit to each and every road segment, instead implementing a simple table lookup (freeway: assume 65 MPH, residential: assume 25 MPH...). This is a highly efficient solution that keeps the data light and the calculation short and simple, so it quickly produces an accurate ETA result. Though I don't find incorrect (or offensive) the suggestion of tagging* prima facie* limits with the tagging syntax specified, I find speed limit tagging to be most useful where there are posted signs with a specific number. That's just me, though. SteveA California The DVD map based nav system in my 10 year old car makes the same assumption about speeds based on its three classes of roads. It had wildly incorrect times until I configured it for California speeds. Now it does a reasonable job at estimating travel times on its selected route if I am in California. But typical rural speed freeway speeds vary considerably from state to state and for longer trips the times are still quite a bit off. Assumed values are not as good as actual values. (And my car nav system always tries for the slow way to the southern SF bay are apparently ignoring that CA 152 exists until I actually make the turn on to it from I-5 when it realizes that my way is both shorter and faster than the route it picked, so it has other problems.) A while back I suggested that prima facie speed limits tags be put the boundary area/relation for administrative areas. So the relation for California could specify something like prima_facie:maxspeed:motorway=65 MPH. This would be a simple to implement scheme with relatively few entries in OSM and be easy to update in the rare situation where the law changes. It could also allow for city or county rules to be specified. Routing algorithms could discover the appropriate assumed speeds for any class of road in an area buy looking at the enclosing administrative boundaries and the tags on those boundaries. But that suggestion was met with a pretty cold response by the tagging mail list. Instead a multitude of roads in Europe and elsewhere are being tagged with the prima facie speeds and having a source:maxspeed tag to explain it. My suggestion in this thread will contributed to that so I admit it is not my first choice. Tod ___ Talk-us mailing list Talk-us@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-us ___ Talk-us mailing list Talk-us@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-us
Re: [Talk-us] Prima Facie Speed Limits
Historical and live speed profiles are pretty much required for trip planning in congested urban areas, but for those of us who drive close to the speed limit and make long trips on relatively uncrowded rural freeways, travel time estimates based on posted (or prima facie) speeds are a good approximation to reality. I travel between northern California and southern Arizona a lot. The distance is about 1,300 kilometers and only a small fraction of that is congested urban freeways (especially if I decide, as I usually do, to avoid Los Angeles). OsmAnd with its knowledge of actual posted speed limits (many entered by me) does a very good job at predicting my arrival time. On Sep 9, 2014, at 11:48 AM, Martijn van Exel wrote: There's a functional difference between speed limits and the actual speed driven. For ETA prediction, speed limit data is not all that useful - detailed historical and live speed profiles are. That is not data that is in OSM (or should be). The speed limits are mostly useful for alerting drivers they may be driving too fast. For a system like that to be feasible you will need comprehensive posted speed limit coverage, which OSM currently does not have. Martijn ___ Talk-us mailing list Talk-us@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-us
Re: [Talk-us] Prima Facie Speed Limits
Agreed - that's a pretty small use case, relatively, though. On Tue, Sep 9, 2014 at 1:38 PM, Tod Fitch t...@fitchdesign.com wrote: Historical and live speed profiles are pretty much required for trip planning in congested urban areas, but for those of us who drive close to the speed limit and make long trips on relatively uncrowded rural freeways, travel time estimates based on posted (or prima facie) speeds are a good approximation to reality. I travel between northern California and southern Arizona a lot. The distance is about 1,300 kilometers and only a small fraction of that is congested urban freeways (especially if I decide, as I usually do, to avoid Los Angeles). OsmAnd with its knowledge of actual posted speed limits (many entered by me) does a very good job at predicting my arrival time. On Sep 9, 2014, at 11:48 AM, Martijn van Exel wrote: There's a functional difference between speed limits and the actual speed driven. For ETA prediction, speed limit data is not all that useful - detailed historical and live speed profiles are. That is not data that is in OSM (or should be). The speed limits are mostly useful for alerting drivers they may be driving too fast. For a system like that to be feasible you will need comprehensive posted speed limit coverage, which OSM currently does not have. Martijn ___ Talk-us mailing list Talk-us@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-us
Re: [Talk-us] Prima Facie Speed Limits
Yes, a pretty small use case at somewhere around 10,000,000 trips per year on I-5 through the central valley of California. Or 9,000,000 trips per year each way on I-8 across the desert to the Arizona border. On your daily commute, you may not need help navigating so much as you want accurate real time information about which routes are moving well compared to others. For me, trip planning and using a navigation device is not for local driving (I mostly use OsmAnd for local driving to help me find errors in OSM data) as much as for getting me to places I don't go on a daily basis. You could say it is a pretty small use case as most people don't drive to or through unfamiliar places everyday, but it is probably the biggest use case for a nav system there is. Cheers, Tod On Sep 9, 2014, at 1:17 PM, Martijn van Exel wrote: Agreed - that's a pretty small use case, relatively, though. On Tue, Sep 9, 2014 at 1:38 PM, Tod Fitch t...@fitchdesign.com wrote: Historical and live speed profiles are pretty much required for trip planning in congested urban areas, but for those of us who drive close to the speed limit and make long trips on relatively uncrowded rural freeways, travel time estimates based on posted (or prima facie) speeds are a good approximation to reality. I travel between northern California and southern Arizona a lot. The distance is about 1,300 kilometers and only a small fraction of that is congested urban freeways (especially if I decide, as I usually do, to avoid Los Angeles). OsmAnd with its knowledge of actual posted speed limits (many entered by me) does a very good job at predicting my arrival time. ___ Talk-us mailing list Talk-us@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-us
Re: [Talk-us] Prima Facie Speed Limits
Thanks for clarifying, Tod. For ETA the congested urban use case is much more challenging to get right, and much more likely to rely on an dynamic ETA estimate. If you're on a multi-hour trip, you're more likely to have scoped out your travel time before you leave and planned accordingly, and if that estimate is off by perhaps 30 minutes, that's usually not the end of the world. For many phone navigation apps, the commuting use case is front and center, because the route people take to and from work will depend a lot on live traffic conditions. (Remember Waze's slogan - outsmarting traffic together, or something). So it's really navigation and ETA going hand in hand to deliver the user the optimal way to work or home. On Tue, Sep 9, 2014 at 3:00 PM, Tod Fitch t...@fitchdesign.com wrote: Yes, a pretty small use case at somewhere around 10,000,000 trips per year on I-5 through the central valley of California. Or 9,000,000 trips per year each way on I-8 across the desert to the Arizona border. On your daily commute, you may not need help navigating so much as you want accurate real time information about which routes are moving well compared to others. For me, trip planning and using a navigation device is not for local driving (I mostly use OsmAnd for local driving to help me find errors in OSM data) as much as for getting me to places I don't go on a daily basis. You could say it is a pretty small use case as most people don't drive to or through unfamiliar places everyday, but it is probably the biggest use case for a nav system there is. Cheers, Tod On Sep 9, 2014, at 1:17 PM, Martijn van Exel wrote: Agreed - that's a pretty small use case, relatively, though. On Tue, Sep 9, 2014 at 1:38 PM, Tod Fitch t...@fitchdesign.com wrote: Historical and live speed profiles are pretty much required for trip planning in congested urban areas, but for those of us who drive close to the speed limit and make long trips on relatively uncrowded rural freeways, travel time estimates based on posted (or prima facie) speeds are a good approximation to reality. I travel between northern California and southern Arizona a lot. The distance is about 1,300 kilometers and only a small fraction of that is congested urban freeways (especially if I decide, as I usually do, to avoid Los Angeles). OsmAnd with its knowledge of actual posted speed limits (many entered by me) does a very good job at predicting my arrival time. ___ Talk-us mailing list Talk-us@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-us
