How to sum overlapping segments of routes created by Network Analyst Route tool solver

[SibelSarper]

After running the Route tool using Network Analyst on my dataset of 80,000 point pairs (O-Ds), many of the routes that are drawn contain overlapping routes. Each of these routes contains a unique value representing the number of commute trips that happen along each route. For the segments of routes that overlap, I would like to sum the attribute information associated to the route to get a total of the number of commuters that cross along each segment of the road network. For example, in the photo, one of the routes between O-Ds is highlighted in yellow. Parts of the yellow route overlap with several other routes that connect other O-Ds. The parts of the route that overlap, I'd like to be able to sum the commuter count associated with each route to the overlapping segments of the route. Is there a GIS process that does this or a series of processes that can? Unfortunately, I don't yet have and python expertise. Could anyone help at all? @MelindaMorang 

Sibel

[SteveRhyne2]

Hi Sibel,

If I understand correctly, you want to identify locations where routes overlap and sum the total trips at those locations. Without writing code to create a process, you might want to consider the following steps:

1. Use the intersect tool and intersect routes. In the output type option, choose point. This will create a point at the intersecting locations where routes cross.
2. Use Split Line at point tool. This will split the routes at locations they intersect. The end result will be matched overlapping segments
3. The final step may be performed in a couple ways. Possibly a spatial join to associate IDs at overlapping segments that can allow you to join data together and summarize your trips.

I hope this is helpful.

Steve.

[JaySandhu]

To solve all the OD pairs, I hope you have loaded them into One route layer with the routename property. Once you solve the route layer, you can run the GP tool, Copy Traversed Source Features. This will create a new line feature class that has all the roads that were traversed by all the OD pair routes. Now you can count how many times the SourceOID is repeated. For example you can use the GP Frequency tool and with the SourceOID as the frequency field and summary another field like the commuter count.

Jay Sandhu

[KyleGonterwitz]

in dealing with a similar problem, I've started by defining the segments from which I want to accumulate the counts.  In a highway system the segments are usually between the exits and intersections to other highways work for that.  I'd create a point somewhere at the center of each highway segment and do some buffers to check that within a distance of those points, I'm only hitting one of the defining counting segments.  Might need to move some of those points around if a couple highways are running close parallel to each other.

Then I would spatial join and accumulate the counts in the individual overlapping routes to those points.  ID join those joint point IDs back to the segments for display and analysis.  

[KyleGonterwitz]

I have some code here that does this.  this code had to deal with actual permitted routes so date and time was also a major factor in aggregating the vehicle counts and weights per day. It might seem complicated at first, but the "monthly stats" function is where the joining happens.

pydot/KTRIPS_Processor.py at master · KDOTGIS/pydot · GitHub