For my undergrad GIS project I am looking at whether left turns only (on UK roads... ie. not crossing traffic) could be more efficient for a delivery driver in a 2.2km radius.

I know it probably won't be, but I'm doing it for the sake of it, to show that I can use the software to the assessors etc.

Using OS Open Roads as a network and ArcMap's network analyst extension, is there a straightforward way to assign different costs to left and right turns? (i.e. make right hand turns take as long as four left hand turns or similar).

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    – Midavalo
    Commented Dec 30, 2016 at 15:42

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ESRI Talks about setting up this here this is in 9.3, so your workflow may be a little different but this should be a start.

Also, I remember hearing in the last few years that one of the big carriers in the US saved a lot of money by only doing right turns (not crossing traffic).


How to set up a global turn delay evaluator:

  1. Start ArcCatalog.
  2. Navigate to the network dataset location in the Catalog tree and double-click it to open the Network Dataset Properties dialog box.
  3. Click the Attributes tab.
  4. Select a cost attribute that has a time-based unit (for example, seconds or minutes).
  5. Click Evaluators.
  6. In the Evaluators dialog box, click the Default Values tab.
  7. Under Type for the Turn element, select Global Turn Delay.
  8. Click the Evaluator Properties button.
  9. Choose how you want to define straight and reverse turns and either accept the default values or enter new ones in the Turn Angles section of the Global Turn Delay Evaluator.
  10. For each turn type in the table at the bottom of the dialog box, enter a turn penalty value in the Seconds column.
  11. Click OK in the Global Turn Delay Evaluator dialog box.
  12. Click OK to close the Evaluators dialog box.
  13. Click OK to close the Network Dataset Properties dialog box.

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