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Service Area finds the area upto a specified break value from one or more locations. You say: "My problem is that I am unsure of how to restrict transfers to trips that have not already occured (i.e. the total accumulated time impedance < departure time of trip) and then how to make the solver adhere to the trip sequences once a transfer has occured." I have tried to understand what this means but cannot. If you want to explain it more perhaps someone can provide a way to solve it. As far as: "I am working on a research project that looks at the maximum distance a person can travel by bus from a given intersection within one hour at specified time intervals, such as 4:00 PM." If you take a look at the Network Analyst tutorial data, the Paris dataset has a pedestrian walk time attribute that lets you model the travel on metro plus walk on roads. You can solve a service area on that data from any location and see how far you can get for a given break value. Is this what you are trying to achieve? The dataset is used in the following tutorial: http://help.arcgis.com/en/arcgisdesktop/10.0/help/index.html#/Exercise_5_Calculating_service_areas_and_creating_an_OD_cost_matrix/004700000060000000/ Regards, Jay Sandhu
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11-18-2010
05:51 AM
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Priyanka, There is not much you can do at the solver level if the address location is not known. Perhaps you can try a different geocoder for those addresses to see if you can get better results. Else you will have to some how get that information and update the stop information by hand. Jay Sandhu
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11-16-2010
06:37 AM
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Priyanka, Glad to know it is working. ArcGIS does not provide a chinese postman problem solver. Their are partners like RouteSmart that have high end solutions. In ArcGIS 10, you can set the Stop property CurbApproach to "No U-Turn" and then set the Route layer property of U-Turns at Junctions to "Allowed only at Dead Ends" and then solve the TSP. It will give you a better solution. As far as symbolizing the route, you can change the line shape to a cartographic line (e.g. the Highway red line) and then edit it's properties to offset the line a few points, add an arrow and edit those properties to repeate the line decorations many times to see arrows placed along the route. Jay Sandhu
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11-12-2010
08:29 AM
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Priyanka, Looking at your mxd, you are not solving the simple route problem but the travelling salesman option by checking on the "Reorder stops to find Optimal Route". With 454 locations, it will take a while to optimize the sequence. I suggest you let it run. It may take about 5 minutes to solve. One thing you can do to make sure that their are no network connectivity issues is to turn of the Reorder option and then solve to make sure a route can be found between all the points. Another thing I will point out is that your stop locations seem to be every house address along many blocks of streets. Do note that if you are trying to solve a chinese postman problem (e.g. postal delivery or garbage pickup) you will probably not get the most optimal result using the travelling salesman problem solver provided by the route solver. Regards, Jay Sandhu
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11-12-2010
05:40 AM
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Since you are getting a message that the network dataset does not support directions then that is the most likely cause. Use catalog to bring up the properties of your network dataset and click on the Directions tab. What does it say there? Does it support directions? If not, you will have to change the properties of this and rebuild your network dataset. Regards, Jay Sandhu
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11-11-2010
06:28 AM
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No facilities found could be for a variety of reason. One could be network connectivity problems. That is, there is no path from the incidents to the facilities. Another could be cutoff imposed on the closest facility, so no facilities are within the cuttoff from an incident. Yet another problem can be some restrictions are on that prevent a path being found. What network dataset are you using? Can you find a path between any pair of incident/facilities using the Route solver? Jay Sandhu
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11-10-2010
07:46 AM
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Priyanka, You can add the excel sheet to ArcMap and then right-click it to either geocode or display as XY to convert the excel sheet into a point feature class. So if you have address data you can geocode and if you have lat/long then you can use the XY option. No need to convert that to something else. Ex 8 in the Network Analyst tutorials also shows how to geocode orders for VRP from an excel sheet called OrderPairs.xls You can see the details here: http://help.arcgis.com/en/arcgisdesktop/10.0/help/index.html#/Exercise_8_Finding_best_routes_to_service_paired_orders/004700000063000000/ Regards, Jay Sandhu
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11-05-2010
07:33 AM
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Another user was having a simillar problem and solved it by moving the data around. Take a look at the following post and see if that solves your problem: http://forums.arcgis.com/threads/15722-ESRI-StreetMap-network-dataset-error Regards, Jay Sandhu
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11-04-2010
02:59 PM
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The free streetmap data that comes with ArcGIS does not contain historical traffic conditions. You can buy StreetMap premium advanced data with that information. You can get some more information here: http://www.esri.com/data/streetmap/comparison.html If you want to make your own, then you can take a look at the Tutorial data that comes with Network Analyst, specifically the San Francisco data as it has been set up with historical data. You can read more about historical data here: http://help.arcgis.com/en/arcgisdesktop/10.0/help/index.html#//0047000000s0000000.htm Regards, Jay Sandhu
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11-01-2010
06:57 AM
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The service area is generated from the lines that are traversed within the distance you specify. So you could turn on the lines and see what portions are getting traversed. Their can be holes in the service area polygons for un-reached areas. Note that you can possibly get more holes when using the detailed method and less when using generalized method. So if you are using detailed, switch to generalized. As far as the spikes, the outer-most ring of the service area polygons is also influnced by the things that are outside the maximum break values. So in areas of dense networks, you will get less spikes but more when there are fewer edges on one side. You can control this by turning on trim and using an appropriate trim distance. The default is 100 meters. If your break values are 100 meters, then make the trim is around 25 meters. Jay Sandhu
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10-21-2010
07:39 AM
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You will need to do convert the table into "two" sets of locations. I can describe the steps and you can automate it in python. You can do this in ArcMap by first adding the excel table. Then use the "Add X Y data" option and create a new point feature class from the first set of coordinates, that is origin_x and origin_y and then repeate the above but using the destination_x and destination_y. Now you can load these one after the other as stops in a Route analysis layer but using the same id mapped to the "RouteName" property. That way, the same row will turn into a single route. You can load in additional points with the same id as more legs of that route. The only thing you have to watch out is the "order". As long as your data is sorted on ID and Leg it should be fine. Try it out in ArcMap and then automate in python using the equivalten GP tools. Jay Sandhu
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10-18-2010
08:33 AM
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Shilpa, It is likely that computing and storing the 172,000 by 4 route shapes and updating them in ArcMap is running out of memory. You can imagine that it is trying to populate an in-memory feature class with 688,000 lines. You can try "chunking" as described here: http://resources.arcgis.com/content/kbase?fa=articleShow&d=30759 However, it looks all you need is the travel time and not the actual route shape geometry returned back, so I will again suggest that you use the OD Cost matrix solver. Make sure to set destinations to 4 and set a cut off (say 30 minutes) and turn off hierarchy and re-solve. Jay Sandhu
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10-15-2010
02:04 PM
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In StreetMap, the network dataset is contained in the streets.rsx folder. Have you copied that as part of copying the rest of the files? Jay Sandhu
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10-14-2010
09:25 AM
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Shilpa, Not sure what is going on...let me understand the workflow, you create a CF layer, add a field to the Incidents called ADD_PT_ID and then do a load locations and map ADD_PT_ID and load fails? Does the type of the ADD_PT_ID field agree with the contents of the ADD_PT_ID field on your data? If you plan to re-use these addresses, perhaps you can run the GP tool call Add Locations to add the location fields once and then when you do the Load Locations, choose the "Use Network Location Fields" to make it load much faster. This will make it possible to "debug" what is going on you will not have to wait for so long each time you load the points while trying to make this process of mapping the ADD_PT_ID field work. And I will suggest couple of other things since you are loading a large number of locations: If you only want the shortest path distances and not the actual route geometry to the four closest, then use the OD Cost Matrix solver as it will go quicker. Here the CF facilities would mean destinations and the CF Incidents would be Origins. Also, if the four closest locations are reasonably close, say 30 minutes, then turn off hierarchy AND put a cutoff of 45 minutes and solve. It will solve much faster as hierarchy works great for long distances and has a larger overhead for short distances (I am assuming you have a hierarchy built into your network dataset). Regards, Jay Sandhu
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10-14-2010
08:23 AM
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Looks like you must have loaded some "delay" value when you did the load locations. Most likely you had a field that mapped automatically to the attr_"length" field. Open up the attribute table for the facilities and see what values are listed for this field. If it is not 0.0 then use a field calculator and calc them to 0.0 For more information on delay, see the topic for Attr_[Impedance] at: http://help.arcgis.com/en/arcgisdesktop/10.0/help/index.html#/Service_area_analysis/004700000048000000/ Jay Sandhu
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10-14-2010
08:00 AM
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