# Network Dataset with one-way streets, ArcGIS 10.3

I want to create a Network Dataset with one-way streets in ArcGIS 10.3. I have an attribute "Direction of Traffic" with four statuses:

1. open in both directions
2. open in pos. direction
3. open in neg. direction
4. closed in both directions

If the latitude value of the endpoint is lower than the one of the startpoint, the status is 2 (pos). An example for a traffic circle (driving right):

• the line from 12 o'clock to 9 o'clock is pos. (2)
• the line from 9 o'clock to 6 o'clock is pos. (2)
• the line from 6 o'clock to 3 o'clock is neg. (3)
• the line from 3 o'clock to 12 o'clock is neg. (3)

How can I use this information to create a Network Dataset with one-way streets?

One way directions have to be set up relative to the digitized direction of the line (affecting the From-To or To-From edge), and cannot detect line orientations relative to a compass or clock face direction. Therefore, I use a domain based on digitized direction, not compass directions.

1. Open in both directions
2. Open in From-To direction
3. Open in To-From direction
4. Closed in both directions

This gives me the freedom to digitize the line in either direction on the circle and still be able to apply a one-way value that will make it flow correctly.

My evaluator restriction expression for the From-To edge is set to: NOT ([Direction_of_Traffic] = 1 OR [Direction_of_Traffic] = 2) (This restricts travel if the line only allows travel in the To-From Direction or is Closed in both directions)

My evaluator restriction expression for the To-From edge is set to: NOT ([Direction_of_Traffic] = 1 OR [Direction_of_Traffic] = 3) (This restricts travel if the line only allows travel in the From-To Direction or is Closed in both directions)

If you choose to always digitize your lines so that a particular set of compass/clockwise direction rules is observed, that is up to you, but I find it much easier to change an attribute than to flip lines, especially if I have already assigned address ranges or other attributes that are sensitive to the line's digitized direction.

My expression is based on a text field, not a numeric domain, but the expression shown is equivalent to what I have written above.

• Do you know of a tutorial that walks through the whole process of drawing road networks? – mmann1123 Nov 5 '17 at 14:19