The Network Analyst Route solver performs a U-turn at a stop even when the U-turn policy is set to 'Nowhere' or 'Only At Dead Ends'.
This occurs because the routing algorithm assumes the vehicle can pull into a stop, for example, in the driveway or parking lot, and then depart the stop in either direction without it being considered a U-Turn.
Solution or Workaround
Set the CurbApproach property on the stops to constrain the direction in which the vehicle approaches and departs the stops. For example, specify that a stop has a right-hand side curb approach, which forces the vehicle to arrive at and depart from the stop with the stop on the right-hand side of the vehicle. This prevents the vehicle from turning around at the stop.
- Right-click on the network location in the Network Analyst dialog box and click the Properties command on the context menu.
- From the Properties dialog box, change the CurbApproach setting to 'Right side of vehicle' or 'Left side of vehicle'.
- Set the default CurbApproach properties on the network analysis layer by opening the Layer Properties of the route analysis layer.
- From the Layer Properties dialog box, select the Network Locations tab and change the default settings for CurbApproach.
The CurbApproach setting is only applied to new stops added to the analysis layer.