I am trying to create 10-minute walksheds from trailheads using the Generate Service Area in the Network Analyst extension. Basically, my input facilities are the trailheads (point layer) and my network is a polyline shapefile consisting of trails and roadways. After creating the network dataset (Sources: trailheads and network, Attributes: Minutes, Travel Mode Impedance: Minutes etc), I import the trailheads as the input facilities and run the service area tool.
However:
1) The 10-minute service areas are not generated for the standalone trailheads that are not connected to the network (given at these trailheads are not necessary on the trails/pathways). I have tried putting the network layers and trailheads in two different connectivity groups and changing the snapping parameters in Add Locations dialog when importing facilities, but nothing seems to be working (please see illustrations ND1, ND2, and ND3).
2) Some trailheads show a 10-minute walking zone in only one direction, although network lines run through them from different directions (please see illustration for clarity).
What can I do so that I can get 10-minute service/areas walking zones for trailheads that are in close proximity but not actually connected to the networks layer? Also, what can I do to generate walk-zones that are not unidirectional bu instead roughly follows the path of the network lines? Any help would be greatly appreciated!
