Inconsistent Drive Time Areas between results from single and multiple time requests!

[MarkSzlazak]

I'm getting inconsistent drive time area overlays with results from a request for a single time compared to a request for multiple times!

For a given location, say:

(37.31761533167621, -122.09192276000977)

If i request a "1 2 3" minute areas map, the shape of the 1 minute area does NOT correspond to the shape of that area with a request for the single "1" minute drive time. Likewise for the single 2 minute drive time. See here:

[ATTACH=CONFIG]24041[/ATTACH]

[ATTACH=CONFIG]24042[/ATTACH]

[ATTACH=CONFIG]24043[/ATTACH]

However, the 3 minute area does correspond in both the single and multiple time requests.

[ATTACH=CONFIG]24044[/ATTACH]

Why is that??

[Anonymous User]

Original User: mszlazak

In case you are wondering what script I'm using then the relevant part is here:

http://google-maps-utility-library-v3.googlecode.com/svn/trunk/arcgislink/docs/examples.html#CoverAr...

[MarkSzlazak]

I have got back no response as to why there is a difference between the coverage areas. Is this the right forum to post this problem?

[MarkSzlazak]

Am I "missing something"???

Is there some major "bug" with the coverage software??

[Anonymous User]

Original User: mhoover12

Someone more knowledgeable than me can correct me if I'm wrong, but during a multiple service area request, all features except the last (outermost) one are "generalized" to help with processing time, at least in Desktop.  It actually appears the opposite is happening here though, and that the outermost or singular ones are getting generalized while the interior multiples are not.

My guess is it's something along these lines.

[MarkSzlazak]

Someone more knowledgeable than me can correct me if I'm wrong, but during a multiple service area request, all features except the last (outermost) one are "generalized" to help with processing time, at least in Desktop.  It actually appears the opposite is happening here though, and that the outermost or singular ones are getting generalized while the interior multiples are not.

My guess is it's something along these lines.

That's weird!

Thanks for the insight.

I don't have any accounts or access to a desktop version of this service since I'm just experimenting with only a browser and some locally stored data on my PC. Could someone please check the appearance of those 1,2 and 3 minute drive times on their Desktop software.

I'd really like to know what I'm dealing with here.

[Anonymous User]

Original User: swingley

Apologies for not replying sooner. You're more likely to get a meaningful response in the Network Analyst forum:  http://forums.arcgis.com/forums/102-Network-Analyst

[MarkSzlazak]

Apologies for not replying sooner. You're more likely to get a meaningful response in the Network Analyst forum:  http://forums.arcgis.com/forums/102-Network-Analyst

Thanks for the lead. I will look there but I then also have a JavaScript api related issue.

Say there is some kind of simplifying going on that depends on whether areas are nested or not then is this behavior controllable from my script? Is there some property that needs to be set to get the same type of result for all drive time areas?

[Anonymous User]

Original User: swingley

You can try setting outputPolygon but in my testing I still saw different results returned when calculating drive-time polygons for 1 minutes versus 1, 2 and 3 minutes. I still say it's best to take this to the NA forum.