topic Re: use an attribute for traffic direction? in ArcGIS Network Analyst Questions

use an attribute for traffic direction?

KevinGooss — Tue, 04 Jun 2013 18:14:28 GMT

can NA use an attribute to determine the flow of traffic on a road feature or is it limited to the digitized line direction?

Re: use an attribute for traffic direction?

JoeBorgione — Wed, 05 Jun 2013 01:13:23 GMT

I use an attribute called.... Oneway. (short integer, nulls not allowed)

It has three values: 0 (zero) which means there is no travel restriction (two way traffic flow); 1 (one) which means traffic restriction to the same direction of the polyline; and 2(two) which means travel restriction to the opposite direction of the polyline. In my geodatabase, the default value is 0 since the majority of new roads are two way.

Re: use an attribute for traffic direction?

KeG — Wed, 05 Jun 2013 12:45:46 GMT

very interesting. but how do you actually use that attribute when building the network? The docs say that One Way restrictions have to be attributes/expressions that evaluate to Boolean. I thought that meant a road was either one way or two way. Unless you are using this in some other way like Connectivity maybe?

Re: use an attribute for traffic direction?

RobertGarrity — Wed, 05 Jun 2013 14:31:27 GMT

A restriction does indeed need to evaluate to true or false. 'True' means 'restricted', but each line feature represents two edges, one in the from-to digitized direction and the other in opposite direction. So you're really restricting individual sides of the street rather than the entire street. Here's a link to a video that has a better description of how it works: http://video.arcgis.com/watch/2112/creating-network-datasets-one_dash_way-streets
Best,
Robert

Re: use an attribute for traffic direction?

JoeBorgione — Wed, 05 Jun 2013 18:28:54 GMT

very interesting. but how do you actually use that attribute when building the network? The docs say that One Way restrictions have to be attributes/expressions that evaluate to Boolean. I thought that meant a road was either one way or two way. Unless you are using this in some other way like Connectivity maybe?

See attached jpeg....