Isochrone generation

[AnandRao]

Hi,

I need to create 300m isochrones for around 2800 bus stops. But for this particular data the generation process is taking too long and stops responding after a while. Please can anyone let me know what could be the reason for this.

I have tried this process before and it has worked fine for other data.

There is enough space in C drive. I tried splitting the bus stops into different shapefiles and run isochrone generation. But not got the result.

Regards
Anand

[RamB]

hi

Arcgis is sometimes slow. But it does the job. May be wait a little longer, the number of stops you have is a big number. Else check your connectivity before you run the tool.

regards,

[JaySandhu]

300 meter is not too large and you should be able to generate the 2800 bus stops relatively quickly. Perhaps there is something else going on with the data. Have you tried running the service areas, 100 bus stops at a time? Maybe that will narrow it down to which set of stops or where in the network data the service area is taking longer to solve? Also, are you using the generalized or detailed methods and what is your trim distance? What is the data source? That is, streetmap or your data?

Jay Sandhu

[MelindaMorang]

Another thing to double check is the impedance attribute you are using.  What is it, and does it have units of meters?  If it has units of, say, miles, and you entered "300" for your break value, then it would be trying to create 300-mile service areas, which could slow it down considerably.

[AnandRao]

hi

Arcgis is sometimes slow. But it does the job. May be wait a little longer, the number of stops you have is a big number. Else check your connectivity before you run the tool.

regards,

Thanks for your reply. Connectivity is fine, but it is still not working

Anand

[AnandRao]

300 meter is not too large and you should be able to generate the 2800 bus stops relatively quickly. Perhaps there is something else going on with the data. Have you tried running the service areas, 100 bus stops at a time? Maybe that will narrow it down to which set of stops or where in the network data the service area is taking longer to solve? Also, are you using the generalized or detailed methods and what is your trim distance? What is the data source? That is, streetmap or your data?

Jay Sandhu

Thanks for your reply.

I tried both generalised and detailed method and not specificing any trim distance. The data is not streetmap but our project data.
Sometimes on few of the data I have encountered the following error

"Error:The index was either too lage or too small"

Once this error is seen Arcmap stops generating service areas.

Can you help me on this please

Regards
Anand

[AnandRao]

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[/HR]

Another thing to double check is the impedance attribute you are using.  What is it, and does it have units of meters?  If it has units of, say, miles, and you entered "300" for your break value, then it would be trying to create 300-mile service areas, which could slow it down considerably.

Thanks for your relpy

I am using metres but not working yet

Anand

[MelindaMorang]

Hi Anand.

Are you trying to generate merged polygons ("Merge by break value" in the Polygon Generation tab)?  If so, this could slow down the analysis considerably, since you have so many input facilities.  If you ARE using Merged, try using Overlapping instead, as this should solve much faster.  If you still want to merge them by break value, you can solve them as Overlapping first and then use the Dissolve tool to dissolve them by break value afterwards.