topic Network Attribute Evaluator help in ArcGIS Network Analyst Questions

Network Attribute Evaluator help

IsabelMcLoughlin — Fri, 10 Jun 2011 19:01:58 GMT

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.

Re: Network Attribute Evaluator help

RobertGarrity — Fri, 10 Jun 2011 20:22:32 GMT

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.

Re: Network Attribute Evaluator help

IsabelMcLoughlin — Mon, 13 Jun 2011 12:30:11 GMT

Thank you very much!