I'm running a location allocation modelling to select 45 air pollution monitoring stations. I keep getting the warning message like
Warning: Location "Location 48" in "Demand Points" is on a non-traversable network element position.
Warning: Location "Location 102" in "Facilities" is on a non-traversable network element position.
The two inputs for the location allocation are demand points and facilities points (no road network involved). The same 341 points were used for both demand and facilities.The value of each point is the spatial variance (the semivariogram calculated by the moving window kriging). The variance was used as the weight for the demand points. For facilities, there is no weight.
I specified the problem type of max attendance, choose 45 locations, impedance cutoff is 1500m. The goal is to capture as many as spatial variance using the 45 locations.
Could anyone please tell me what might cause this warning message?
Thank you very much