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

I have never split a way before. I want to correctly split and re-attach the ways for the right turn filter lanes which go around the pedestrian islands for traffic from north going west, and traffic from south going east.

Here is a screenshot of the intersection

Filter lane from north going west - the right turn lane starts a way back on the road from the north, is this where the way should be split?
The way going east is split by a divider. The way is not in the center of the road. Where should the added way be re-attached to the way going east?

Filter lane from south going east - the right turn lane starts a way back on the road from the south, is this where the way should be split?
Where should the new right filter lance way be re-connected to going east?

Lastly, I have annotated the right turn lanes already using lane and road attribute. When I add right turn filter ways should I remove the existing right turn lanes?

Thank you very much for your teachings



There is not screen shot, and not link to the existing feature on the map!

A as a general principle, you want to retain as many of the original objects as possible.

Details of how to do the change will depend on which editor you are using.

I am using JOSM

The image link is at

I don’t yet know how to post images :frowning:


Thanks very much hadw, I had no idea I needed to add jpg to the end of the URL

I will also make it a practice to include the OSM lat/long link

Would you happen to know how to correctly split and reconnect ways in JOSM?



A lot of this depends on how much detail you want to provide. Providing too much detail can be messy, as you end up seeing things like multiple junctions where lanes intersect each other.

However, I would start by mapping the 47th Avenue as a dual carriageway (might be UK English), i.e as two one way streets, joining together in the middle of the junction. Ideally also map the barrier between them.

If Elder Creek Road is physically split, I’d also map that as dual carriageway. You can then attach your Southbound filter lane attaching to just the Westbound lane, at the correct physical position.

You will need turn restriction relations on the filter lane. You probably also need them on the through lane, although they are more difficult to justify from what is visible, from the image, of what is on the ground.

As you’ve split Elder Creek Road, the Eastbound filter lane only connects to that side of the road. I’d probably extrapolate a smooth curve to meet that side of road, drawn along the existing dashed line, and join them around the third dash.

You shouldn’t have both explicit lanes and lane attributes representing the same lanes.

You need to find the URL of the actual image, not the page containing it. I used right click view image.

Be a bit careful about terms of use when doing this. I couldn’t find any restrictions, but these sites often make money from advertising on the page that contains the image.

In JOSM, I selected node which is where the right turn lane starts on Stockton Boulevard south of intersection, and tried to split the way from the Tools pulldown menu but I get the error message "The way cannot be split at the selected node (Hint: select nodes in the middle of the way.) This node is one of the nodes on the Stockton Boulevard way.

What am I missing?

So I used the simple editor which appeared to work. I now have a perpendicular way to the right filter lane, is this OK?



As far as I can tell, that node was already at the end of the ways (ie. the way had already been split), so no additional splitting is necessary.

Not quite. You wouldn’t make a 90 degree right turn followed by a 90 degree left turn to get into the turn lane. It should be a more gradual veer to the right, similar to the gradual veer to the left from the end of the turn lane onto Elder Creek Road.

Also, rather than split the turn lane into two sections with different names and highway classifications, a better choice would be to use highway=secondary_link and without any name at all. That’s generally how these type of turn lanes are tagged (with the appropriate *_link, of course). This page has more info on how the link ways are generally used.

Thanks alester,

I removed the right turn lane from Stockton Ave from south. I replaced the named way with an un-named secondary way, removing the right angle connections, which I split and assigned as right turn, the connecting ways from Stockton and to the Elder Creek Road way I did not assign attributes to.

Does this look OK now?

If so, then I’ll work on the suggestions of dual carriageways by hadw

Best Regards;)


I’ve looked that the tags of the simple and JOSM editors and cannot find anything that looks like dual carriageway, i.e. a road with directions physically separated. Can you pretty please point me in the right direction?

Thanks :stuck_out_tongue:


A dual carriageway is not done with tagging alone: You draw two separate carriageways and add oneway=yes tags to each.

When I do this, I usually look at the direction arrows by each node in the existing way and see which way it was drawn. I then move that way to be aligned with the appropriate direction and add the oneway tag. Then I draw the other way where it should be. Finally, I copy all the tags from the original way (including the newly added oneway=yes tag) and paste them onto the new way. That whole operation is much easier if you are dealing with a single way that has not been split up for things like adding turn lanes, etc., so I usually do the change to dual carriageway prior to doing turn lanes.

The method n76 describe is fine for the simple tags, but there is a potential problem with relations when you “split/duplicate” a way to represent a dual carriageway.

E.g. public transport routes are represented as relations in which the way is a member. JOSM (or one of it’s plugins) has a method to copy relations from one way to another. This would be easy, but you introduce a oneway. This means that half of the relations should contain the way in one direction and the other half have to contain the other direction.

It’s pretty hard to explain in a few words, so I can understand you might be scared by now. Please don’t, do what n76 described and ask for help here on splitting the relations.

Fortunately, there are no relations currently mapped, but they would have required handling for filter lanes, as well.

Also, I don’t think the filter lane should be considered a secondary road, particular the bit that is part of the residential road. I’d need to think more carefully as to what it should be.

The need for a filter lane at all, or two lanes in each direction, makes me question whether the residential road really is a residential road, or whether it is, maybe, tertiary, or unclassified.

Thanks n76, escada, and hadw,

Regarding the right turn from Stockton to Elder Creek, which is tagged as secondary. I see this conceptually as 3 entities:
1 - a link from the Stockton Boulevard way
2 - a right turn filter lane
3 - a link to Elder creek Road way

I added a one way attribute and smoothed out the turn. What I wonder is the meaning of “Secondary link”? in JOSM (There are also a primary and tertiary links). Should 1 and 3 above be “links” or unclassified ? Should 2 be unclassified?

Regarding turning 47th street into two ways, it currently has Lane and road attributes which I will remove and follow n76 recommendations then add Lane and road attributes back in, unless I hear differently

Thanks very much



So I split 47th avenue - I don’t know if I did it correctly at the split/merge nodes. I also added Pedestrian Crosswalk to nodes on the two unidirectional ways near the intersection. Before I do the same to Stockton Boulevard north of the junction, would you kindly see how much of a mess I made with 47th Ave and let me know?

So I went ahead and split Elder creek into a dual carriageway, it looks strange with the Lane and road attributes visible on the way that connects dual carriageway to non-carriageway, is this the correct way to do this?

Also…in the non physically divided section of Elder Creek, there are two lanes in both directions with a middle lane having orange lines. It seems that this is for traffic in both directions so I selected that in the Lane and road attributes and got the error message shown below.

What is the correct way to tag the center lane using Lane and road attributes?

Thanks for your help;)



The lanes tagging should be something like:


FWIW, the “turnlanes - tagging” plug in for JOSM makes this much easier two work with.

Hi N76

Yes that is what I did :smiley:

The error message on the map says Invalid turn:lanes both_ways value

Any ideas?



Thank you for posting a link of the area. It allowed me to see the satellite imagery without the OSM data so I could figure out how I might tag it from scratch.

It looks to me that the section you have tagged as turn:lanes:both_ways=reversible has the paint striping typical of a “center turn lane” even though it does not have the arrows painted in the middle (I think many/most newer center turn lane roads in my area are also missing the arrows, perhaps that is no longer part of the California version of national recommendations.) In any case, the more usual tagging for a center turn lane is to use turn:lanes:both_ways=left. I did that on your section and the error/warning in JOSM went away. I did not save my changes as I usually try to limit my editing to areas I have actually visited or am planning on visiting and it will probably be a while before I get to the Sacramento area.