I need advice on fixing this intersection

[rotus8]

https://www.waze.com/editor/?zoom=6&lon=-122.03218&lat=37.31575&layers=BFTFTTTFTTFTTTTTTTTTFT&segments=61274390,61666158
I am not sure how to fix this, but it is not working as indicated by multiple URs. The two turn lane segments (highlighted in the permalink I think, at least I tried) seem overly complicated, but I don't see a reasonable way to configure it to work.

I do see there is a bad turn restriction on the upper turn lane segment at the south, turning back on itself, but I am not sure that will fix everything.

[CBenson]

Well, at the very least the right turn off of this segment should be restricted.
Edit: Yeah, I'm not sure that will fix everything either.

[AlanOfTheBerg]

Yeah, it's messy. One thing to do to reduce bad routing, as shown by one UR, is to not junction the turn lanes with anything except the cross street. Make them a lower (or higher) Level and just allow the turn lane to cross De Anza.

This segment is unnecessary unless you add a street segment as a parking lot segment prior to it. That's the only reason the segment exists, right?

Is the straight-ahead on this segment really restricted?

[rotus8]

Thanks Alan. Changing the level of the turn lanes and not connecting them to the straight through helps. Good catch on that turn restriction; I think it has been there a long time and no doubt contributed to the routing.

Yes the extra bit is for access from the parking lot, but it was there before and is in the intersection striping, so I think I'll leave it in for now.

I have made changes now and would appreciate a double check, and any comments for improvement.

[rotus8]

OK, I also added the parking lot road for completeness.

[kellyhirano]

As a noob question, should De Anza be two one-way roads? It splits south of El Camino, but I'm not entirely sure why. There's a median north of El Camino and El Camino itself is listed as a two-way road and has a similar configuration to De Anza. I'd like to make De Anza a single, two-way street, but that seems like quite the effort and I don't want to do it without some discussion first.

[shawndoc]

As a noob question, should De Anza be two one-way roads?

Yes, it should. Take a look at the Wiki, and it gives 3 reasons why you should split a road:

A road should be split if:

1 GPS tracks show a clearly definable gap (blank area) between the color-by-azimuth arrows at the 100m zoom level.
2 U-Turns are required to properly make turns that are blocked by a median.
3 It is an Interstate Highway (USA) or other Limited Access Highway using the "Freeway" road type.

You'll notice it has a raised median, and several side streets and businesses can only be accessed from one side, requiring drivers to drive to the next intersection and make a U-Turn to get to those businesses. So it meets #2 above.

[kellyhirano]

Yes, it should. Take a look at the Wiki, and it gives 3 reasons why you should split a road:

A road should be split if:

1 GPS tracks show a clearly definable gap (blank area) between the color-by-azimuth arrows at the 100m zoom level.
2 U-Turns are required to properly make turns that are blocked by a median.
3 It is an Interstate Highway (USA) or other Limited Access Highway using the "Freeway" road type.

You'll notice it has a raised median, and several side streets and businesses can only be accessed from one side, requiring drivers to drive to the next intersection and make a U-Turn to get to those businesses. So it meets #2 above.

Thanks, that makes sense. So by that logic, there are all kinds of errors in the South Bay Area:

1. S Mathilda Ave (it's the same as De Anza further south) changes from a two way road to two one-way roads at El Camino on the map here. Based on #2, it should be two one-ways all to the north. El Camino itself should also be two-way. And while the Wiki directly says that Google Maps is not a reason to do it, it's consistent with two one-ways for both of these roads.
2. W Caribbean Drive (which S Mathilda Ave turns into) should also be two one-ways.
3. All of Lawrence Expressway has a raised median, so it should also be two one-ways.
4. Much of Great America Parkway also has a raised median and should be two one-ways.
5. Montague Expressway also has a raised median and should be two one-ways.
6. San Tomas Expressway also has a raised median and should be two one-ways.

Though in more reading of the wiki, it says there are reasons to not split a road:

There is a curb or non-drivable median less than 5m wide between lanes of travel (see exceptions above).
The non-drivable median is interrupted by a cross segment at most intersections.

So it sounds a bit like it could go either way on the areas I outline above. The median varies, but I'm guessing it's <5m for many parts and there are cross segments at "most" intersections. That's definitely fuzzy.

I'll leave it all as is. The inconsistency along the same physical road (De Anza/Mathilda) just bothers me.

[shawndoc]

The general rule is don't change it if its not generating complaints.