Restriction for one direction on a bi-directional segment

250
4
07-19-2011 04:53 AM
Highlighted
New Contributor
I'm working on an application to route oversize vehicles.  I've built the network dataset from the Navteq data and have applied a number of restrictions to route oversize vehicles.  One remaining issue has to do with mast arm features which affect travel in only one direction on a bi-directional road.  Mast arms typically extend over only part of a road:  i.e. an overheight truck would not be able to pass going northbound, but southbound is OK because the mast arm only extends over the northbound side of the road.  Applying a network height parameter on that segment causes the route solver to avoid that segment regardless of direction of travel.  I would like to be able to allow southbound travel, but not northbound.  The feature class represents the road as a single line feature, its "DIR_TRAVEL" attribute is coded as "B" to allow travel in both directions.  Am I missing some Netowrk Analyst capability that can help with this issue?
Tags (2)
Reply
0 Kudos
4 Replies
Highlighted
MVP Esteemed Contributor
I'm not familiar with Navetech data but in the network datasets I've built I use a oneway attribute that has a coded domain of 0,1,2 with o being the default value.

A value of 0 allows no restiction. A value of 1 restricts direction of travel to the direction of the line: from node to node. A value of 2 restricts the direction of travel opposite of the line: to node from node.

Perhaps you could use a similar approach in your application.
Reply
0 Kudos
Highlighted
New Contributor
Joe:

Thanks for the suggestion.  Navteq data does have an attribute associated with direction of travel ("B" for travel in both directions, "T" for travel in the "to" direction of the line, and "F" for travel in the "from" direction).  The problem I have is, I can't be 100% certain that all northbound travel is in the "T" direction of the line, for example.  The direction of the line may be counter to the listed direction of travel. 

Bob
Reply
0 Kudos
Highlighted
MVP Esteemed Contributor
The only thing I can suggest is dig into the data and see what's going on.  It doesn't matter if it's 0,1,2 or B,F,T; you may need to split the streets and code them as needed. 

Anything in Network Analysis is data-intensive and data-sensitive.  One of the short comings of the national brand data sets is they are one size fits all.  Until you find out it doesn't fit you!

Good luck
Reply
0 Kudos
Highlighted
New Contributor
Joe:
I figured that that would be the case, but it never hurts to try to see if anyone has figured out some clever solution to these quirky problems. 
Thanks for taking the time to respond,
Bob
Reply
0 Kudos