The solution provided by the Route, Closest Facility, OD Cost Matrix, or Service Area solvers traverse a network element that is blocked with a point barrier. Solvers should avoid the barriers.
The point barrier is placed in a location where coincident network elements exist.
When placing a point barrier in ArcMap, only one barrier, NALocation, is created on one network element by the NALocator agent.
Because the point barrier is only restricting one of the coincident network elements, the route is passing through one of the other unrestricted coincident network elements.
Solution or Workaround
At 10.0, additional barrier types have been added to Network Analyst, including line and polygon barriers. To restrict multiple coincident network elements, simply draw a line barrier across or a polygon barrier around these coincident elements.
Prior to 10.0, properly restricting all network elements underneath a barrier required the creation of one point barrier per network element. Follow the steps below to do this.
- Determine how many coincident network elements are underneath a barrier.
- Use the Identify tool in ArcMap to determine the ObjectID for each network element.
- Create one barrier NALocation per coincident network element. For example, if there are three coincident edges, create three barriers.
- Right-click the point barrier in the Network Analyst Window and select Properties.
- Modify the SourceOID for each barrier to match ObjectIDs obtained in step 2.