Network Analyst - Linear Referencing

[ShaunConway]

Hello Everyone,

Background - Local Government, ArcGIS Server 9.3.1, SQL, Local Government ELA

We have recently discussed linear referencing with our traffic engineers. We are looking to take advantage of linear referencing to handle such attribution as speed limits, lane counts, traffic counts, truck and height restrictions etc.

One of our main concerns moving forward is directed towards the interaction of linear referencing and networking/routing.

How does this design (linear referencing) interact with network analyst?

Will the attribution still be accessible for use as network attributes (impedence, cost, restrictions etc?)

Will we need to export event layers to feature classes in order for network analyst to access the data?

We would really appreciate any advice and guidance going forward. Thanks in advance!!!!
Shaun

[MattCrowder]

Nework datasets use fields on the source feature classes to determine network attribute values.  It can not directly use linear referencing where attribute values change partway along a feature.  As you suggest, the solution would be to export the event layers to true feature classes where the features are split where attribute values change.  For example, if you have one linear feature line1 that is 10 miles long and has a speed of 35 MPH for 30% and 45 MPH for 70% and you want your speed to be a network attribute, you would nedd to create 2 features in a feature class, one 3 miles long with a speed of 35 MPH and one 7 miles long with a speed of 45 MPH.

Hope this helps,

Matt

[ShaunConway]

Thanks Matt - This helps us plan out our next few steps. If you don't mind, I had another question. Are there any tools out there for updating the event tables through ArcMap? We are looking for something along the lines of
- Select a feature
- View associated event table instances
- Update/add/delete event table instances

We have a distributed group of folks who will be managing the event tables --- most of which do not have much GIS experience.

Thanks Again Matt,
Shaun

[AndrewPerencsik]

You can't edit events by starting with line features and going from there how you describe, at least not without making a custom program for this. You can edit events by selecting them and opening the Attributes dialog, and then editing their values. You can also edit them in the Table window.

There is this sample code for adding events:

http://resources.esri.com/help/9.3/ArcGISDesktop/com/samples/Linear_Referencing/Editing/Digitize_Eve....

It's unsupported, but it may cover some of your needs.

Andrew

[GrantHopkins]

Hi Andrew,

Will this sample code run in ArcGIS 9.3.1? Do you think ESRI would ever implement and support this sort of tool? This would be very helpful.

Thanks,
Grant

You can't edit events by starting with line features and going from there how you describe, at least not without making a custom program for this. You can edit events by selecting them and opening the Attributes dialog, and then editing their values. You can also edit them in the Table window.

There is this sample code for adding events:

http://resources.esri.com/help/9.3/ArcGISDesktop/com/samples/Linear_Referencing/Editing/Digitize_Eve....

It's unsupported, but it may cover some of your needs.

Andrew