Calculating freight cost in a network dataset cost attribute

ConnieSu

Hello! I have a network dataset with roads and railways (line features) and railway terminals (point feature). I want to calculate the freight cost based on the distance in kilometers. The freight cost is equal the distance multiplied by a constant, that depends on the transport mode.

I've added a freight cost attribute, firstly with an "others" unit and secondly with a "distance - kilometers" unit. I've tried the field script equal to [Shape]*constant and [Shape_Length]*constant, but in all tries I did not achieve the expected result, that would be the distance (in kilometers) multiplied by the constant.

Please, could somebody help me and tell me what I'm doing wrong?

Thanks and regards!  

Melinda Morang

Can you give more details on what you mean by "I did not achieve the expected result"?  How was it different from what you expected?

In general, your approach seems correct.  You just want to scale the distance by some factor and report that as the freight cost.

My current suspicion is that the spatial reference of your data does not have units of Kilometers.  If it's in Meters or decimal degrees or something, the values returned by the Shape or Shape_Length fields will be in those units and not kilometers, so you'll get the wrong values.

You could precompute a field in your source feature classes that has the distance in Kilometers.  Or, you could use a function evaluator to combine your freight cost factors with your existing distance attribute that's already in Kilometers (for that case, where the Shape or Shape_Length fields are read directly, the network dataset does the unit conversion for you automatically).