Network Attribute Evaluator help

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06-10-2011 12:01 PM
IsabelMcLoughlin
New Contributor
I have created a network for determinging pedestrian travel time over a rural set of roads. I have classified the roads based on condition, I would like to use these road classes in my travel time cost attribute.
Example:
If road type is 1,2, or 3 then speed calculation should be Length of road * 60(minutes)/5500(meters)
If road type is 4,5 or 6 then speed calculation should be Length of road * 60(minutes)/3500 (meters)

How to I create this into one network attribute evaluator?
Any help or advice would be appreciated.
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2 Replies
RobertGarrity
Esri Contributor
Hello, IsabelM. Let's assume you have two attributes on your source feature class that represents rural roads: Meters and RoadClass.

1. Create a network cost attribute.
2. Set the evaluators for the to-from and from-to directions of the roads source to be field evaluators and set their pre-logic section to the following:

result = 0
Select Case [RoadClass]
Case 1, 2, 3
result = [Meters] * 60/5500
Case 4, 5, 6
result = [Meters] * 60/3500
End Select

3. Set the "Value =" text box to result.
4. Build the network.
5. Optionally, verify the values for roads are what you expect by using the Network Identify tool on the Network Analyst toolbar.
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IsabelMcLoughlin
New Contributor
Thank you very much!
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