I'm trying to run a Service Area with NA. I'm using airports and I want to impose limits. One is a 30 minute drive time, and the other is a 30 mile radius. I know this will take two steps, but as I am trying just the 30 min drive time, I don't think it's working the way I thought/need it to. Any help would be greatly appreciated.
- Nicole, please be more specific what's wrong and what are your analysis parameters if you want a specific answer.
Some thoughts may be to check if you chose proper attribute containg time as Impedance, check if your network dataset was created with proper setting for time attribute. - I have the time in minutes, and when I run the new service area, I use my airports point file as the Facilities. When I hit solve, the resulting polygons around the points do not look like I thought they would. They almost look like octopus. I don't have every local road, should I put that as part of my route system?
- Nicole- perhaps you could post up some screen shots of your network parameters, that might help. If at all possible, if you can provide a portion of your streets? I'd be happy to build a network and see if I can replicate your problem.
I don't think missing a few roads is your problem. - [ATTACH=CONFIG]17877[/ATTACH][ATTACH=CONFIG]17878[/ATTACH]
Here are some snapshots. The polygons around some of the airports do not look like they are only 30 miles in any direction from the airport.
I've been using the new route from NA, but this is my first time using Service Area.Attachments
- Are those 30 miles or 30 minutes? Either way, they look okay to me. It appears that you have some connectivity issues in the south west part of Idaho. Clearly the big gaps you have in central Idaho are due to a lack of roads; not many in the Frank Church and Hells Cyn wilderness areas, right?! You may want to explore the various settings on how to display your service areas; obviously you've got some overlap.
May I suggest you concentrate on your data and run some individual tests from those airports that appear suspect; you can run some simple point to point routes and your connectivity issues will show up in in a hurry.
Hope this helps- Are those 30 miles or 30 minutes? Either way, they look okay to me. It appears that you have some connectivity issues in the south west part of Idaho. Clearly the big gaps you have in central Idaho are due to a lack of roads; not many in the Frank Church and Hells Cyn wilderness areas, right?! You may want to explore the various settings on how to display your service areas; obviously you've got some overlap.
May I suggest you concentrate on your data and run some individual tests from those airports that appear suspect; you can run some simple point to point routes and your connectivity issues will show up in in a hurry.
Hope this helps-
It's 30 miles. But when I run 30 mins, it shows up the same, and it shouldn't be. Some places that are 30 miles from the airports are more than 30 mins. As for the central part of Idaho, it's all mountains, so there aren't a whole lot of roads - that I expected. I want the overlap, because I want it to show for each point.
I will check the data again, and post if I have any further questions.- Without actually seeing how you set your network up, I don't want to venture a guess as to why your 30min/30mile analyses look the same, unless all your roads are 60mph and I doubt that. Something is fishy; but you know that already!
Best of luck- - Try the following two things to diagnose more:
1. Use the network identify tool (second icon from right on the NA toolbar) and click on a street to see what is the reported length and time attribute. They should not be same unless there is a problem in setting them up.
2. In the places where you see more problems, Turn on the service area line generation and then re-solve. Now you can see what roads were traversed in the 30 minutes and you can use the normal identify to see how far they got to (FromCumul_ and ToCumul_ field values).
Jay Sandhu - Thanks Jay, that helped alot!
1. Use the network identify tool (second icon from right on the NA toolbar) and click on a street to see what is the reported length and time attribute. They should not be same unless there is a problem in setting them up.
2. In the places where you see more problems, Turn on the service area line generation and then re-solve. Now you can see what roads were traversed in the 30 minutes and you can use the normal identify to see how far they got to (FromCumul_ and ToCumul_ field values).
Jay Sandhu