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

hadw · 2017-12-13T16:43:53.000Z


[IMG]https://i.imgur.com/ZSW1v7D.jpg[/IMG]

https://www.openstreetmap.org/?mlat=38.51050&mlon=-121.43587#map=19/38.51050/-121.43587

PhilCJ · 2017-12-13T17:01:36.000Z

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?

Regards

Philcj

hadw · 2017-12-13T17:05:19.000Z

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.

hadw · 2017-12-13T17:07:57.000Z

PhilCJ:

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

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.

PhilCJ · 2017-12-15T16:04:02.000Z

In JOSM, I selected node http://www.openstreetmap.org/node/5215105016 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?

Regards

Philcj

alester · 2017-12-15T18:29:45.000Z

PhilCJ:

In JOSM, I selected node http://www.openstreetmap.org/node/5215105016 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.

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.

I now have a perpendicular way to the right filter lane, is this OK?

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.

PhilCJ · 2017-12-19T18:50:02.000Z

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;)

PhilCJ

PhilCJ · 2017-12-19T21:38:32.000Z

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

PhilCJ

n76 · 2017-12-20T03:36:00.000Z

PhilCJ:

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

PhilCJ

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.

escada · 2017-12-20T13:52:18.000Z

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.

hadw · 2017-12-20T14:06:59.000Z

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.

PhilCJ · 2017-12-20T18:46:17.000Z

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

Regards

PhilCJ

PhilCJ · 2017-12-20T20:49:09.000Z

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?

PhilCJ · 2017-12-21T15:24:42.000Z

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.

https://www.openstreetmap.org/?mlat=38.51050&mlon=-121.43587#map=19/38.51050/-121.43587

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

Thanks for your help;)

Regards

PhilCJ

n76 · 2017-12-21T15:54:51.000Z

PhilCJ:

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.

https://i.imgur.com/scOLwbn.jpg

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

Thanks for your help;)

Regards

PhilCJ

The lanes tagging should be something like:

lanes=5
lanes:forward=2
lanes:backward=2
lanes:both_ways=1

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

PhilCJ · 2017-12-21T16:33:11.000Z

Hi N76

Yes that is what I did

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

Any ideas?

Regards

PhilCJ

n76 · 2017-12-21T17:31:43.000Z

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.

PhilCJ · 2017-12-21T22:23:00.000Z

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 https://www.openstreetmap.org/edit#map=19/38.51045/-121.43748 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?

Regards

PhilCJ

n76 · 2017-12-22T00:53:46.000Z

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.

hadw · 2017-12-22T10:50:16.000Z

I still don’t believe that Elder Creek Road is a mere residential road. E.g. https://www.openstreetmap.org/way/23972516#map=16/51.5793/-0.3110 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.