It is important to understand that Waze uses a penalty-based routing system. It computes the total penalties for a route and selects the one with the least cumulative penalty. Therefore it is possible for big detour routes to occur when the primary route is extremely slow.

Conversely an "uninterrupted name" is defined as a series of segments in middle of a route which do have an identical name on all the segments (with the exception of a single isolated segment among them).

Conversely an "uninterrupted name" is defined as a series of segments in middle of a route which do have an identical name on all the segments.
NOTE: There is no single isolated segment exception.

To be considered as a possible detour there must be a Freeway / Highway segment of the same 'Road Type Group', which share any name, both before and after a series of segments which contain a name-discontinuity, and are in a different 'Road Type Group'.

To be considered as a possible detour there must be a Freeway / Highway segment of the same 'Road Type Group', which share any name, both before and after a series of segments (more than one) which contain a name-discontinuity, and are in a different 'Road Type Group'.

DwarfLord wrote:

PesachZ wrote:Should be updated to say:

To be considered as a possible detour there must be a Freeway / Highway segment of the same 'Road Type Group', which share any name, both before and after a series of segments (more than one) which contain a name-discontinuity, and are in a different 'Road Type Group'.

I'm not quite following the language...the second change (above) appears to contradict the first?

Specifically, the phrase "more than one [segment] which contain a name-discontinuity" in the second change appears to contradict the previous change indicating that even one segment's worth of name discontinuity qualifies as an "interrupted name".

Perhaps I missed something in the context of the remainder of the article...I didn't go back to review it.

CBenson wrote:What do the "name-discontinuity" and "uninterruped name" concepts add to understanding the BDP? Would this be correct?
https://wiki.waze.com/wiki/User:CBenson ... Mechanisms

DwarfLord wrote:

CBenson wrote:Would this be correct?
https://wiki.waze.com/wiki/User:CBenson ... Mechanisms

If I am understanding the clarification, the following paragraph from the above link may make an incorrect implication:

CBenson's draft wiki article wrote:If the ramp does not also carry a simple alternate name of "I-1234", then there is a discontinuity of the highway name between the concurrency and the continuation highway. If there are two ramp segments like this, it will trigger Big Detour Prevention unexpectedly, and Waze will create an unneeded penalty for continuing on I-1234.

Based on the clarification, I think the discontinuity of the highway name for even as much as a single segment will trigger the unexpected penalty. The above paragraph leaves the strong impression that there need to be two segments with the name discontinuity to trigger the unwanted penalty.

This may be a big deal, actually, as we are not always able to set ramp alternate names to reflect concurrent highway names without unwanted side-effects on BC and thus navigation instructions.

DwarfLord wrote:Still, it may be more helpful to reword to something like "If there are two or more ramp segments for the concurrent highway, but even one of the segments does not carry the simple highway name as either primary or alternate, Waze will impose an unexpected detour penalty for continuing on I-1234".

Provided I'm understanding the mechanism myself, that is.

CBenson wrote:Regarding the Criteria section, the significant differences that I see between my draft and your proposals are:

1) I've eliminated the "to be considered as a possible detour" paragraph. Even if the routing algorithm operates with a two step process, I'm not sure it matters to us if as long as "detours" are a subset of "possible detours." My reasoning assumes they are. That is there are no "detours" that meet the criteria for "detours" but are not penalized because they weren't evaluated because they failed to qualify as a "possible detour."

2) The current wiki defines "name-discontinuity" as a series of segments that . . . . The possible detour statement refers to "a series of segment that contain a name-discontinuity." I've read this to mean that the possible detour can be comprised entirely of segments without the relevant street name or can include some segments that have the relevant street name as long as one is missing the relevant street name. This fits with my understanding of the BDP, so I'm pretty sure this is correct.

3) There has been some confusion regarding the road type limitation. The wiki states: "The possible detour is not composed of the same 'Road Type Group' as the continuation after the possible detour." The first question is does "not composed" mean does not include any segments of the same 'Road Type Group' or does it mean does not include all segments of the same 'Road Type Group.' My experience tells me this should mean "does not include all segments." In other words the detour must include at least one segment that is not in the same 'Road Type Group.' The second question is that the 'Road Type Group' limitation is also mentioned in the possible detour paragraph and seems to modify the series of that contains the "name-discontinuity" series. If this is intended to mean that a segment with the 'Road Type Group' discontinuity must also have the "name-discontinuity," then I do not believe I've included such a requirement in my draft. (It is usually the case, for example a ramp segment with the name discontinuity, but I don't know if its required or not).

4) The final difference that I see is that I have changed criteria 5 regarding the one segment rule to refer to the possible detour rather than the name continuity. I'm fairly certain that this is the basic change that needs to me made even if my other suggestions are not adopted.

edsonajj wrote:If I'm understanding the proposal correctly it seems to imply that if on a route that takes you out of a road and soon after it takes you back, name discontinuity on a single segment would cause detour prevention to kick in.

That would contradict what I see on this route since it takes you out of a road and back again with a name discontinuity in the middle.

Could someone tell me if I misunderstood the text of the proposal?

PesachZ wrote: However in practice today the process is not always applied exactly precisely due to server processing limitations. Therefore to be safe and future proof if you want to ensure a specific behaviour, then you should ensure compliance from all the segments of the possible detour.

CBenson wrote:I don't know. I don't think its good practice to name cross streets between a divided highway with the name of the highway in order ensure compliance with a shifting BDP implementation.

A "possible detour" is a series of segments (more than one) in the middle of a route which meet the minimum criteria to trigger an evaluation.

edsonajj wrote: But what if it is, like on my example, a crossing with an overpass? According to the article I should put name A on the connecting ramps and in one segment of road B.
Mind you, that would very probably suppress the instruction to exit right on the ramp.