topic Re: Network Analyst - Speed due to Slope in ArcGIS Network Analyst Questions

Network Analyst - Speed due to Slope

IonutAlixandroae — Wed, 16 Apr 2014 08:59:47 GMT

Hello, I have a question regarding slope used in network analyst. If I have the elevation, maximum speed, length and the slope of the network, how can i find the time spent using these parameters? Also, I need to put a condition on slope, that the speed will modify due to slope differences, and with the speed the time spent.
I think I need a python script, but i`m not sure.
Can you help me please?

Thank you,
Ionut Alixandroae

Re: Network Analyst - Speed due to Slope

RamB — Wed, 16 Apr 2014 09:15:20 GMT

You can use the simple formula of kinematics, you can search for "velocity along a inclined plane"

Just not to repeat myself, you can look here

regards

Re: Network Analyst - Speed due to Slope

IonutAlixandroae — Wed, 16 Apr 2014 10:44:20 GMT

OK, so if I have segments of my road, and each one of them have attributes of Min_Z, Max_Z, Mean_Z, Speed, Segment length, Min_Slope, Max_Slope and Average_Slope, how should I write in Field Calculator?
Thank you !

Re: Network Analyst - Speed due to Slope

RamB — Mon, 28 Apr 2014 11:05:45 GMT

Hi,

It depends on where (s) you want your velocity (Vf) depending on your slope (theta).

if you have the details at s , then you can calculate the speed. For example if you want to calculate at the middle of your segment, you can take s = half of length of that segment, theta you can interpolate between your two slope values and speed you can take of the previous segment (Vi) and then find Vf

you need to be careful about your direction of travel because then the theta will be positive or negative based on your conventions.

regards,