Divided roadways and U-turns

Map Editors Community United States Georgia
1

I’ve seen a number of URs reporting that Waze suggested u-turns at an intersection, but u-turns are not allowed. This seems most common on a divided roadway where a cross-section is added for left turns and cross over points. In a number of cases, a u-turn is NOT allowed at these left-turn/cross over points, but there doesn’t seem to be a way to represent that.

For example, the highlighted segment in the link below shows all possible turns enabled. However, on Riverside Parkway, from both directions, the left turn lane has a No U-Turn symbol. Yet the way this is set up, Waze will suggest a u-turn there if necessary.
https://www.waze.com/editor/?env=usa&lon=-84.03556&lat=33.96620&layers=997&zoom=8&segments=66996028

Is there a better approach to this, or should I give the standard “please use your best judgement when following any GPS’s directions”?

Any idea how other regions approach this problem?

Edit: This link provides some guidance:
https://wiki.waze.com/wiki/Best_map_editing_practice#When_.28Not.29_to_Split_a_Two-Way_Road

The most interesting one is that roads do not need to be split to match satellite views, especially if it makes routing more complicated.

2

So is the no u-turn “symbol” new? Is it a sign on the road, or painted? Either way, just shorten the segment you have highlighted to less than 15m and make all turns as close as possible to 90 degrees. This is a common issue we deal with all the time, and it depends on the intersection what method is best. There is supposed to be a new/better junction tool coming “soon”.

3

Thanks for the answer. Just to answer your question…the no U-turn signs have always been there. They are signs cemented into the median across from the end of the left turn lane so you are looking right at the sign while waiting to turn.

Also, as a relatively new editor, I’m not sure I understand the technical reason for your advice. Could you explain how shortening the cross connection to less than 15m helps? Is there something special about that length (or shorter) that causes the segment to act differently in routing, specifically in preventing U-turns? Is that something I’ve missed in the Wiki (which is entirely possible…I’m finding new stuff all the time).

Thanks again!

4

Hmm…ok. I only see signs that say to go to the right of the median on streetview. That is why I thought they were new. Maybe I’m looking at the wrong thing?

5

Ok, not quite what I remember. It looks like there are no signs between traffic lights, but here’s two at the lights (the first at Lakes Parkway, and the second at Hwy 120):
https://www.google.com/maps/@33.9632387,-84.0371694,3a,75y,11.58h,88.04t/data=!3m4!1e1!3m2!1s0Y11_qB6kdE1_YCpGlRAhA!2e0
https://www.google.com/maps/@33.9680197,-84.0354243,3a,75y,35.75h,82.55t/data=!3m4!1e1!3m2!1s-gMkE82ZOOpnnug9bv7rQg!2e0

So it looks like the sections between the traffic lights don’t have a u-turn restriction, but the intersections at the lights do, and the way the map is drawn, could try to route a u-turn there. There are other examples around the county (and country, I assume), but I thought this one would have good visuals as to what I’m talking about.