Latest Contributions by JaySandhu

What inappropriate u-turns are taken when you have intersection/dead ends option selected? Perhaps that may point to some connectivity issue in the network (or many restricted edges) that cause no route to be found when you choose the dead ends only option. Jay Sandhu ... View more

You can review the connectivity of the network dataset by adding it to ArcMap and then using the network identify toolbar on the Network Analyst toolbar. Click on the new edges and see if they are connected to the relevant edges. Jay Sandhu ... View more

To find best sequence to visit a set of stops is called the Traverlling Salesman Problem. You can use the Network Analyst Route Solver. After loading your 25 stops, bring up the properties of the route solver and on the Analysis Settings tab, click on the option to Reorder Stops to Find Optimal Route. More info here: http://help.arcgis.com/en/arcgisdesktop/10.0/help/index.html#/Route_analysis/004700000045000000/ Regards, Jay Sandhu ... View more

The geometric network is ideal for utilities and network dataset/network analyst for transportation networks. The main difference is that geometric networks have the concept of "flow". i.e. something moving along the network in a defined way. So you can perform tracing upstream/downstream. It does not have concepts such as turn restrictions, turn delays, street name for directions, etc. Network dataset supports these navigation type capabilities. Network Analyst is a licensed extension that operates on these network datasets. Geometric networks are part of core ArcGIS. Hope that helps to clear up some confusion. Regards, Jay Sandhu ... View more

Looks like they already have a network dataset in that feature dataset and when trying to create a new it will complain that there is no feature classes to add to it. So, delete the network dataset first and then create a new one as in the tutorial. Jay Sandhu ... View more

You can also look at the following post on how to get the location on the road where a point may snap to and it's distance. http://forums.arcgis.com/threads/29022-Can-points-be-automatically-moved-to-the-street-lines Else, the OD CostMatrix is perfect for computing road/network distances between sets of locations. http://help.arcgis.com/en/arcgisdesktop/10.0/help/index.html#/OD_cost_matrix_analysis/00470000004r000000/ Jay Sandhu ... View more

Have you gone through the Network Analyst Tutorials? http://help.arcgis.com/en/arcgisdesktop/10.0/help/index.html#/About_the_ArcGIS_Network_Analyst_tutorial/00470000005r000000/ Jay Sandhu ... View more

There are no out of the box tools to do this. But I can give you some pointers on how to get it done in workstation Arc/Info. First thing you need is the X,Y coordinates that correspond to the from and to nodes. To do this, run the AddXY command on your node coverage. This will add two fields. Now you can use them based on your nodeid mapping to get the x,y's of each node. The second part is about creating a coverage from your edge list. Look at the IMPORT command. This will create a coverage based on X,Y coordinates. You could EXPORT a small line coverage and see the format. BUILD the line coverage with line and node opions and then use JOINITEM to add the edge weights based on some unique ID of each line you imported. You can draw the lines with "offset" to see two lines between each pair of nodes by using a line symbol with ARCLINES command that has been "offset" by using the LINEOFFSET command. Jay Sandhu ... View more

Make a network dataset on your street network and then use the GP tool, Calculate Locations to compute the "street" locations of your point dataset. Make sure to click on the "Network Location Fields" to expand that and specify the names of the optional Located X and Y-Coordinate Fields. Now when you run the tool, it will add the X,Y of the location on the street where the point would snap to. You can then use these fields with the Add X,Y data and make a new feature class with updated locations. You can read more on this tool here: http://help.arcgis.com/en/arcgisdesktop/10.0/help/index.html#/Calculate_Locations/004800000006000000/ Regards, Jay Sandhu ... View more

Most likely you have not added a travel time impedance attribute to your network dataset. That is, the service area solver will give you an option to change the impedance attribute to any of the supported attributes. So use ArcCatalog (or catalog in ArcMap 10) to bring up the properties of the Network Dataset and click on the Attributes tab and see if you anything but Length listed there. If not, you will have to add one, set its evaluators and Build the network dataset again. Jay Sandhu ... View more

You do not need to create topology to create a network dataset. However the creation of correct network topology relies on connectivity. If your data is well constructed with end points meeting each other, etc then it should be fine. If you do not have good topologically connected data then you will have to work with the topology tools or the Integrate tool to first get your data in a good shape for network dataset creation. Jay Sandhu ... View more

It is hard to say what number will work, but how about processing 100k at a time. That way if it works you can repeate it 20 times and get the work done. Jay Sandhu ... View more

Are you running on a 32 bit OS or 64 bit OS? ArcGIS 10.0 can access up to 4 GB only if running on a 64 bit OS else it is limited to 2 GB. Also you may want to run the solve as a background GP process as that will have less overhead on RAM instead of running the OD solve in a foreground process. If all your 55,000 points are in the DC area, say within one hour of each other, then put a cutoff of 90 minutes and turn off the hierarchy and then solve. It should not run out of memory for 100 by 55000 as it will not have to compute the backward trees which really help in long distance routing with hierarchy. You need to add the cutoff in case you have some unreachable locaions (due to restructions) and then it will keep searching the entire network before giving up and can run out of memory. Jay Sandhu ... View more

How far apart are your 55000 points. Are they within a city or spread out more? Do you need a complete matrix or can you get away with values limited to some cutoff distance? Jay Sandhu ... View more

I looked at the screen shots and here is what I think is going on: First, your connectivity model is not correct as the local and minor roads are in their own connectivity group and DO NOT connect the major roads, highways, etc. If you want to maintain these two groups, you will have to create a junction feature class and bring that in and have it span the two connectivity groups. I suggest you look at the Paris data in the network analyst tutorials for examples. This would explain why your service area crosses over the highways. That is, they are not connected to the local roads and the service area sovler will not know they are even there. Second, it is not clear how you have defined the restrictions. How is the evaluator set up? Your screen shot on the attributes has a restriction field set to all 1's. Does that mean all roads in that connectivity group are restricted? That would explain why you get the message that facilities are located on non-traversable elements. Third, your network dataset says it is not built. So perhaps you made some changes and have not built it again. Hopefully you can fix the connectivity, build and try again. Jay Sandhu ... View more