calculating route diistance

Question

Hi
I am trying to find out the shortest path between a point (which is projected to equal distance) and some school locations. I have built a network layer using Fairfax road and trying to load the locations as stops by using the load location tool. but whenever i try to solve it says "Stops" is on a non-traversable network element position". 
I also tried the OD matrix to solve without showing the routes but it says the same. i don't understand where i did mistakes. my road layer has a restriction of 'oneway'. I also want to find out driving direction. I am really stuck and trying this for a week. What should i do now?
Any help is really appreciated. 
Subrina

TunagginaKhan · Answer

🙂 
Thank you so much Robert

The deadend with one way was also new for me 😄

Thanks again
Subrina

RobertGarrity · Answer

Hello Subrina,

Hope you're well. Judging from the graphic you posted, there is surely a problem with the Oneway restriction attribute. It is restricting your roads in both directions, rather than just one. Furthermore, it's restricting two-way roads--probably all of them. I say this because the road you identified in the graphic was a dead end and should be two-way--I've never heard of a one-way deadend before. 🙂

You'll need to correct the logic in your evaluator for the Oneway restriction attribute. The logic should look something like what's shown in the 5th and 6th graphics in the following help topic: 
http://help.arcgis.com/en/arcgisdesktop/10.0/help/index.html#/Types_of_evaluators_used_by_a_network/00470000000n000000/

You may want to go through the first Network Analyst tutorial exercise and pay particular attention to Step 24 when you choose Oneway. Also during that step, click the Properties button (on the right side of the dialog box) to get to the evaluator's logic.
http://help.arcgis.com/en/arcgisdesktop/10.0/help/index.html#/Exercise_1_Creating_a_network_dataset/00470000005t000000/

One other thing to consider is you can use the nationwide network dataset that comes with the Data & Maps DVD instead of making a network dataset yourself, and avoid some difficulties. But that's only if your study area is in North America or Europe.

Best,
Robert

TunagginaKhan · Answer

Hi Robert

Sorry for late replying. I was sick. Actually i am thinking which one is the evaluator logic in the one-way restriction attribute? But i did the service area as you said and found that many of my centroid locations are on one way road. so i cannot find a service area away from that point. but my q is: if it is a one way there should be another road to the opposite direction. yet i understand ...it is the data layer which shows no alternative road to come back. 
for hospitals, i have created the service area from centroids and can find out how many hospitals are located within certain distance from the centroid points along the network.
Thanks for your suggestions.

Subrina

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