[Page update] At Grade Connectors

Moderator: Unholy

Re: [Page update] At Grade Connectors

Postby sketch » Wed Dec 03, 2014 8:29 pm

I am not gonna blame this on Waze. A user has a duty to look at the damn road when using GPS.

Waze says "turn right on Street Name" and you turn on "Different Road", that's your fault for looking neither at street signs nor at the Waze display. One or the other and you'd know better than to make that turn.
ALL US EDITORS READ: New USA road type guidance
assistant regional coordinator • south central region • usa
waze global champ • usa country manager • new orleans
2017 chevrolet ss sedan 6mt • slipstream blue metallic
Image Image
sketch
Waze Global Champs
Waze Global Champs
 
Posts: 10940
Joined: Sat Aug 08, 2009 6:13 pm
Location: New Orleans, LA
Has thanked: 1614 times
Been thanked: 2154 times

Re: [Page update] At Grade Connectors

Postby sketch » Sat Nov 29, 2014 11:27 pm

I wouldn't be that aggressive, but I would certainly give some scrutiny to the AGCs. I believe I proposed that 50 m was the approximate breaking point for a "stay to the" AGC without a physical separation, but that where there is a physical barrier, there should nearly always be an AGC, unless the distance is really small.

Final turn instruction depends on speed, not on road type (I think).
ALL US EDITORS READ: New USA road type guidance
assistant regional coordinator • south central region • usa
waze global champ • usa country manager • new orleans
2017 chevrolet ss sedan 6mt • slipstream blue metallic
Image Image
sketch
Waze Global Champs
Waze Global Champs
 
Posts: 10940
Joined: Sat Aug 08, 2009 6:13 pm
Location: New Orleans, LA
Has thanked: 1614 times
Been thanked: 2154 times

Re: [Page update] At Grade Connectors

Postby sketch » Fri Sep 12, 2014 6:43 pm

CBenson wrote:
sketch wrote:OK, so, the "penalty" is only when there is a detour. There was no detour in this case.


They said this:
3 road type issue, we have a high penalty when you're on major highway -> exit to ramp -> enter to primary street, to solve it try to change the ramp to primary street or major highway

to mean the small detour prevention?

I thought the road type had to be the same for the highway you are detouring off and back on. I also didn't think primary streets played any role in the small detour prevention. Are saying that if you go MH>R>PS and the major highway and the primary street have the same name/city (or alternate name/city) the small detour prevention kicks in?

Look at the cell next to that where I left a comment. There's a short thread between me and Ron where we discuss this. It took me a few minutes of thought to understand it, but it eventually sank in.

You're talking about large detour prevention; this is a small detour prevention example. Small detour prevention is the thing that's supposed to stop straight-U-right-instead-of-left and other similar routing foibles. Of course it doesn't require you to have the same name or type at the start and end because you're making a turn. Past that, we don't know the criteria it uses.

But it's designed to give you a normal left turn instead of a U-right or right-U. It's not designed to give you a jughandle instead of a U-right. So since the U-right is faster, and there's no normal left, small detour prevention isn't triggered.
ALL US EDITORS READ: New USA road type guidance
assistant regional coordinator • south central region • usa
waze global champ • usa country manager • new orleans
2017 chevrolet ss sedan 6mt • slipstream blue metallic
Image Image
sketch
Waze Global Champs
Waze Global Champs
 
Posts: 10940
Joined: Sat Aug 08, 2009 6:13 pm
Location: New Orleans, LA
Has thanked: 1614 times
Been thanked: 2154 times

Re: [Page update] At Grade Connectors

Postby sketch » Fri Sep 12, 2014 3:51 am

CBenson wrote:
sketch wrote:Or we need to get them to remove that penalty.

Any word on the status of this penalty. If they aren't going to remove/change it, then we should implement their advice not use ramp type for jughandles.

OK, so, the "penalty" is only when there is a detour. There was no detour in this case.

The route took a straight-then-U-then-right instead of the jughandle because the former was faster at that time. Oddly, when I test in the live map, the jughandle is always the alternate route, no matter which time I select (random sample, I didn't check every single one). When I test using the WME route checker, it usually does the straight-U-right route, but a couple times of day did give me the jughandle. It does seem that the jughandle takes significantly longer.

My guess is that, since the jughandle is not a conventional left turn, the small detour prevention tool doesn't prefer it over the straight-U-right. Since the straight-U-right is faster in fact, it is used.
ALL US EDITORS READ: New USA road type guidance
assistant regional coordinator • south central region • usa
waze global champ • usa country manager • new orleans
2017 chevrolet ss sedan 6mt • slipstream blue metallic
Image Image
sketch
Waze Global Champs
Waze Global Champs
 
Posts: 10940
Joined: Sat Aug 08, 2009 6:13 pm
Location: New Orleans, LA
Has thanked: 1614 times
Been thanked: 2154 times

Re: [Page update] At Grade Connectors

Postby sketch » Sat Aug 30, 2014 1:24 am

qwaletee wrote:So to clarify, in a roundabout, if a MH runs "through" it, we are counting both parts of the road individually, so by definition, unless the MH portion terminates at the roundabout, you effectively always go for that MH, because it is always at least two segments.

I can think of some unusual examples that would make the rule not make sense, but I understand where you are coming form now. however, that precise definition wouldn't work for AGCs, because you wouldn't want to count the two segments of MH that might exist at one end separately.

The more exact definition, but very technical, would be:
Take the highest road type connected to the roundabout/AGC. Describe all routes through the roundabout/AGC that start or end on that type. If any of those routes start and end on that TYPE are also of the same type, then make the roundabout/AGC that type. if not, then take the highest road type that routes to/from the first road type, and use that as the type of the roundabout/AGC.

Right, like I said, it's per segment, not per road. (A split road is counted as a single "segment" – you can "collapse" it into a single two-way segment of that type.) It's explained well on the roundabout page, linked in the post above yours.

The same logic can be used to determine the type of a complex AGC. Judging by the geometry, you can only take the AGC from EB One to Two or to EB Three, so only 3 segments connect to it: EB One (west side of image), Two, and EB Three (east side of image). Three segments: MH, S, MH. Type of second-lowest segment: MH.

If Three were PS instead, then three segments: MH, S, PS. Type of second-lowest segment: PS.

Even if the AGC were accessible from both sides of One, the AGC is not used to get from one side of One to the other, so it can be "collapsed" into a single MH for the analysis – because that connection doesn't need to be analyzed. Same if both sides of Three were accessible from the AGC.
ALL US EDITORS READ: New USA road type guidance
assistant regional coordinator • south central region • usa
waze global champ • usa country manager • new orleans
2017 chevrolet ss sedan 6mt • slipstream blue metallic
Image Image
sketch
Waze Global Champs
Waze Global Champs
 
Posts: 10940
Joined: Sat Aug 08, 2009 6:13 pm
Location: New Orleans, LA
Has thanked: 1614 times
Been thanked: 2154 times

Re: [Page update] At Grade Connectors

Postby sketch » Fri Aug 29, 2014 8:55 pm

Not the second highest type, but the type of the second-highest-type segment. So if two are MH, it's MH.

It's the lowest possible level that provides full continuity. If you use the roundabout to get from an MH to another MH, the roundabout needs to be MH. If you use the roundabout to get from an MH to an mH, it only needs to be an mH to provide full continuity.

A typical AGC uses the lower of the TWO types because it connects only two types, and the lower one provides full continuity while keeping the type as low as possible. Of course, a strange and complex AGC might exist that connects multiple segments. In that case, the roundabout rules should be used to set the type of it as well.
ALL US EDITORS READ: New USA road type guidance
assistant regional coordinator • south central region • usa
waze global champ • usa country manager • new orleans
2017 chevrolet ss sedan 6mt • slipstream blue metallic
Image Image
sketch
Waze Global Champs
Waze Global Champs
 
Posts: 10940
Joined: Sat Aug 08, 2009 6:13 pm
Location: New Orleans, LA
Has thanked: 1614 times
Been thanked: 2154 times

Re: [Page update] At Grade Connectors

Postby sketch » Sun Aug 24, 2014 10:21 pm

qwaletee wrote:Sketch,

In the case you are giving (40m solid white followed by 30m physical separation), we could force a keep right for the initial turn lane followed by a turn right (using hackery unfortunately), if we needed to give the dreaded early lane guidance without compromising the turn direction itself. Or am I missing something here?

Only that AGCs aren't generally used for simple single-white-line turn lanes.

If a normal turn lane is...
-- ROAD -- TURN LANE DELINEATED BY SOLID WHITE -- INTERSECTION

And a separated turn lane is...
-- ROAD -- TURN LANE DELINEATED BY SOLID WHITE -- DIVERSION FROM PARALLEL -- INTERSECTION

In the first situation, the "typical intersection", we don't put in an AGC for the turn lane, so the turn instruction is timed from the intersection itself. This works fine in most cases, so typically turn lanes like that aren't drawn in. You're already expecting the turn, so you should already be in that lane anyhow. In the second situation, we put the AGC in at the point where traffic diverges from parallel to the normal lanes. That's the point where, like the intersection itself in the first situation, you actually turn and face a different direction, so it's the point where users would expect to hear the instruction. Users don't expect the instruction at the start of the solid white line with a normal turn lane, so they shouldn't with one that diverts from parallel either.

Now – this is really just the most common situation, and I won't say that there won't be situations where a "stay right then turn right" isn't appropriate. But it's generally not necessary. It's less common, also, because right turns are a lot easier than left turns, so they don't typically get special treatment by traffic engineers the same way that left turns do.
ALL US EDITORS READ: New USA road type guidance
assistant regional coordinator • south central region • usa
waze global champ • usa country manager • new orleans
2017 chevrolet ss sedan 6mt • slipstream blue metallic
Image Image
sketch
Waze Global Champs
Waze Global Champs
 
Posts: 10940
Joined: Sat Aug 08, 2009 6:13 pm
Location: New Orleans, LA
Has thanked: 1614 times
Been thanked: 2154 times

Re: [Page update] At Grade Connectors

Postby sketch » Fri Aug 22, 2014 9:36 pm

PesachZ wrote:I mostly agree with your sentiment, except the 50m rule. If the AGC is deemed necessary, I believe it should split of the road at the commitment point, the point which past that you are no longer legally allowed to make that turn if you are in the wrong lane. This is especially helpful in complex intersections where otherwise a route make try to make that turn illegally after joining the road past the commitment point, from the wrong side.

The commitment point is a good place to put the "stay left" if the AGC is designed to give a "stay left" followed by a "turn left" for particularly long or physically separated turn lanes or particularly complex intersections.

However, for AGCs designed to give a "turn" instruction at the start point of the AGC (in the case of, say, physical separations), the commitment point is not the optimal location. I'm not sure if you meant to include or exclude those, but I want to make it clear. Putting it too early has the disadvantages of (1) the turn instruction leaving the screen too soon, (2) the next prompt spoken too soon, and (3) inconsistency with timing of non-AGC turns. Consider a 40 m solid white line for a normal right-turn lane, then a 40 m solid white line leading to a 30 m physical separation. We wouldn't add an AGC to make the former sound sooner, so we should keep that in mind when designing the latter. The "turn" instruction is expected to be based on the actual point where the turn is made, whether you are guided by a physical island or not.
ALL US EDITORS READ: New USA road type guidance
assistant regional coordinator • south central region • usa
waze global champ • usa country manager • new orleans
2017 chevrolet ss sedan 6mt • slipstream blue metallic
Image Image
sketch
Waze Global Champs
Waze Global Champs
 
Posts: 10940
Joined: Sat Aug 08, 2009 6:13 pm
Location: New Orleans, LA
Has thanked: 1614 times
Been thanked: 2154 times

Re: [Page update] At Grade Connectors

Postby sketch » Wed Aug 20, 2014 10:13 pm

PesachZ wrote:Another thing to consider, if ramps do indeed introduce penalties, what is their effect when used in Wayfinders?

Sent using Tapatalk for Android 4.4.2

They say the penalty is when going from MH to Ramp to PS. So a ramp used between two equal segments shouldn't incur a penalty.
ALL US EDITORS READ: New USA road type guidance
assistant regional coordinator • south central region • usa
waze global champ • usa country manager • new orleans
2017 chevrolet ss sedan 6mt • slipstream blue metallic
Image Image
sketch
Waze Global Champs
Waze Global Champs
 
Posts: 10940
Joined: Sat Aug 08, 2009 6:13 pm
Location: New Orleans, LA
Has thanked: 1614 times
Been thanked: 2154 times

Re: [Page update] At Grade Connectors

Postby sketch » Wed Aug 20, 2014 9:40 pm

Okay, but then you also have to change all the segments that were edited following that guidance first.
ALL US EDITORS READ: New USA road type guidance
assistant regional coordinator • south central region • usa
waze global champ • usa country manager • new orleans
2017 chevrolet ss sedan 6mt • slipstream blue metallic
Image Image
sketch
Waze Global Champs
Waze Global Champs
 
Posts: 10940
Joined: Sat Aug 08, 2009 6:13 pm
Location: New Orleans, LA
Has thanked: 1614 times
Been thanked: 2154 times

Next

Return to Wiki Updates and Discussion

Who is online

Users browsing this forum: No registered users