Correct way to split ways at 4-road intersection for right turns?

Hi n76,

Thanks for taking a look, I made the change and saved it without error. Maybe the straight error is some kind of bug.

I have an issue with the results of making 47th Avenue a dual carriageway. Somehow I have an extra way that I don’t know how to delete.

It is at on the eastbound part of the 47th ave

Can you suggest a way to delete the section to the right of the node where the dual carriageway nodes join?



The dual carriageway was not actually connected to the two way section of 47th and there was no node on the two way section of 47th to split the way (to delete the extra). A difficulty was that there were two administrative boundaries that were sharing nodes with the road system, that always makes things harder. The short fix for that was to add a node to the “extra way” where where the dual carriage ways should connect to it and merge the nodes between that and the dual carriage ways. Second, to split the extra way and then delete the unneeded section.

I took the liberty of editing 47th between 54th and Elder Creek Road to show you how I’d do it. I hope you don’t mind. . .

Generally we don’t tag direction arrows (turn lanes) unless there is paint on the pavement. So I removed many of the “through lane” tagging.

I thought the intersection of 47th/Elder Creek and Stockton would be cleaner if the dual carriageways were not converted to single carriageways for the intersection alone. There were no traffic signals tagged at that intersection but from the imagery there appears to be signals there so I added them. I usually use the “tag incoming ways” method of adding traffic signals to an intersection if anything coming into it is a dual carriage way. I don’t normally tag crosswalks but the crossings were there already so I added footways but only for the intersection itself.

Between Steiner and Wire there is a service/access road parallel to 47th, if it follows the convention I see elsewhere in California it is likely also named 47th but I can’t tell from the imagery so I added it as an unnamed unclassified road, you will probably want to see what it is actually called and fix it.

The main reason I added that service/access road is because there was a service road at 38.5106202,0121.4415917 that erroneously connected to 47th but the imagery indicated it actually connects to the service road.

All these edits assume, of course, that the ERSI imagery I was looking at is current.

I still don’t believe that Elder Creek Road is a mere residential road. E.g. is much more residential in character but is still classified as tertiary. The only traffic you should expect on residential roads is vehicles accessing housing on that road and on the directly connected residential roads.

Hi n76,

Thank you for investing your time to help me, you fixed my problem anticipated my next question about how to draw ways across intersections. I did make minor modifications to the lane count in the intersection. I liked your idea of keeping the lane count the same as the source way until the left turn way, so I applied it to throughout. I have to say that I really don’t like the way-star configuration where there is a central node for the intersection such as 47th Ave and Wire Drive…but that is for another day.

Your are correct the parallel road is also 47th Ave.

Do you know a pointer to adding lights using “tag incoming ways” ? I see you already took care of that but I’d like to know how to do.

Thank you also for putting in the pedestrian ways. I may extend these. This prompts one question that I’ve had for a long time, the width of the foot path is a configurable tag. I am looking how to tag widths for lanes, I see it in the OSM description but have not found it in an editor, do you do if there is an editor which supports configuring lane widths?

Hi hadw,

I agree with you, should it be secondary like Stockton, or Tertiary?



I am not aware of a tool or plug in that helps on tagging traffic lights. On one way highways it is easy, just put a node where the stop point is and then add a


tag. On two way highways you also need to add a


tag where forward/backward is the direction the traffic signal affects flow with respect to the direction the way was draw.

Stop signs are similar but, unfortunately the direction tagging does not use something like stop:direction but rather


. The direction tag also has a totally unrelated semantic for other types of objects like mine entrances, etc. where the direction is either in degrees or north/south/east/west. I made mention about that use of one tag name with multiple contradictory uses on a tagging mail list and did not make much headway in getting people to acknowledge the problem much less consensus on what to do about it.

I’ve not done much lane width tagging and haven’t looked for a plug in to help.

My personal rule of thumb is that if there is no painted center line the road is unclassified, residential or service. If the authorities decided it is enough of a feeder to paint a center line then it is probably at least a tertiary. For suburban/urban roads, if it is mostly divided then it is probably at least secondary.

Urban primary to me is harder to define, at least now that I am in Orange County. In the Bay Area it seemed to be pretty clear: They were the main roads one would take that did not quite make the cut to be counted as a Santa Clara County expressway. However in Orange County there are a fair number of roads that people don’t seem to consider as major yet they are divided, often with three or more lanes in each direction, with speed limits of up to 55 MPH and relatively few traffic lights. In Santa Clara County they’d almost be expressways but here they people seem to feel they are of secondary importance. I often punt on these, leaving the classification as I found it and take solace in knowing that if the speed limits and traffic control (lights, signs, etc.) are properly tagged then navigation apps will find the best route regardless of the tagged classification being secondary or tertiary instead of primary.

I looked at the whole of 47th Ave and Elder Creek Road and set to Tertiary since part of it was already Tertiary.

I looked for plugins that set lane width but could not find any. How do you edit the raw OSM code to add tags when not supported by an editor?



Using JOSM: With the object(s) selected, in the “tags” area on the right there is a “+ Add” button. Click on that. You can type what ever you want for the tag name in one field and tag value in the other field.

My guess is that for width of lanes you’d use the *:lanes tagging scheme. Default in OSM for measuring is meters. So assuming a one way road with three lanes, with the lane widths from left to right of 10ft, 10ft, 14ft I think you’d tag it:


Edit: From the wiki page on width at, it looks like you can use the typewriter style single and double quote to specify feet and inches. So I think you could tag the above example as:


Thanks n76 !! (I have a big question at the end)

In JOSM when you click on + Add button in the tags section you get a dialog box that says this will change up to 1 object, it asks for:
1- a key with a pulldown menu, width was a choice but I could type in width:lanes :smiley:
2 -a value with a pulldown menu, I could type in 12’0"|12’0" :smiley:

Check out

The newly added tag even shows up in the simple editor under all tags, but if you click on the information it says “There is no documentation for this key”

The OSM XML looks like this

OK so now for my big question (drum roll): I would like to be able to associate a polygon with geo co-ordinates for each lane and way segment. Do you think this is possible, if not, how close to that do you think is possible?



The tagging of width:lanes=* looks okay to me. Tag Info shows that width:lanes=* is not widely used (more in Europe than elsewhere). And while there is no wiki page documenting it, the :lanes and width= semantics are followed.

I am not sure I understand you follow up question. I suspect that you want to map the outline of the roadway was an area. There is a semantic for that (polygon tagged with highway=* and area=yes). Is that what you’d like to do? It does not seem to be widely supported by either map rendering or more specifically navigation apps. I suspect that most navigation software is broken with respect to handling that properly.

Thank you hadw, alester, escada and n76

I think the junction is now looking good (although probably not perfect)

I took my broader polygon question for a new application to a new Forum topic “Polygon for each street segment that has different rules”

Any further suggestions would be appreciated

Thanks again