ct13 wrote:I think a helpful addition to this page would be something that explains the road type classification on segments that are part of divided road intersections. It would be provide instructions on how to assign road types inside of the intersections, similar to the roundabout road type page.


"When road segments of 2 different types converge at divided road intersection, choose the highest road type of the parallel, intersecting segments. Doing so will ensure that high priority roads are not unduly pruned by the routing algorithm at an intersection."


Here is an extreme example of the type of graphic that could used to illustrate this point.

1.png

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ct13 wrote:Maybe we can spin this off into a new topic or move to the correct place?

PesachZ wrote: Though I would argue that by our AGC rules in the US the two medians you set as MH, should really be mH. making them mh will have no detrimental on routing here.

If we followed AGC rules, it seems like the turn from the PS to the MH or the mH would be adversely effected by having the median segment set as street type. I think that having it be the highest segment type is a much simpler rule than following the AGC rules except when the road group changes; for instance, "when MH and street meet, defer to the highest type, but when 2 types of highways meet, pick the lowest of the two." would be much more confusing for a negligible (or arguably worse) change in routing. One size fits all rules are always easier to remember and since there is a bigger downside associated with choosing a lower road type than a higher one, this would err on the side of caution.

PesachZ wrote:The issue will be that the guidelines fo this kind of thing varies by country. Perhaps it is better placed in the page for Median Uturns, and have that page expanded to cover all median typing in the USA.

That sounds like a good place for it. Additionally, a link from the Road Types/USA page from this sentence would also seem appropriate.

Wiki wrote:Special rules are used to determine the road types of roundabouts and at-grade connectors.

1. Assess each possible route through the segment.
2. List the lower road type for each route.
3. Choose the highest type on the list you made in step 2.

codgerd wrote:Hi all,

A discussion started recently on the Canada unlock forum as to best practice in terms of placing the junction node of an exit ramp. The wiki guidance on the Interchange page recommends placing the first geometry node of the ramp segment level with where the solid line starts at an exit i.e. at the last legal decision point to take the exit, and to put the junction node itself prior to this point such as to make a 10 - 15 deg angle with the roadway.

https://wiki.waze.com/wiki/Junction_Sty ... complexity

As (at least in Canada) it seems that in practice there is a wide range of configurations employed for ramp geometries and the wiki guidance is clearly not being followed in any consistent way, I raised the issue with my local champ mentor, who in turn raised it with the Canadian and US champs and routing experts.

I gather that the discussion is still ongoing, but it seems that the emerging consensus is that this may not in fact be the recommended guidance; rather, it seems that it should be the junction node itself that be placed at the last legal decision point, not the first geometry node of the ramp segment.

If they arrive at a full consensus on this, I suspect it will be brought to the wiki community's attention via other channels, but I thought I would raise the issue here to allow for any discussion that may be deemed appropriate.

Cheers
codgerd

jondrush wrote:OK guys, I think I figured this out. I'm normally approaching the ramps at 70-80 mph. The other night I was stuck behind a truck doing 50, and sure enough the last exit call-out was too early. So it appears the Waze is not doing it's sums correctly when calculating the timing for the announcement. But for now, I think the classic guidance of first geo node at the gore point is still correct. You really, really don't want a late ramp call at 75 mph. Early is still better.

Then next step is to make Waze aware of the problem and see if they can fix the timing. To solve the second problem of the next command appearing too soon, I'd like to formally request that Waze delay the switch on ramps.

PhantomSoul wrote:Some of this may also just require editor intuition, too. I mean, if Waze doesn't consider how many lanes you may have to cross to get to an exit, the junction may need to be set back further for a highway with, say, 5 lanes than a highway with just 2, no?

Also, sometimes, we may have to cut a ramp name short so that its readout can finish in time to announce a quick subsequent turn/exit, but that's another topic, I think.